The 2022 Annual Meeting of stockholders (the “Annual Meeting”) of A10 Networks, Inc., a Delaware corporation, will be held on Friday, June 24, 2022 at 10:00 a.m. Pacific Time, at 2300 Orchard Parkway, San Jose, California, for the following purposes, as more fully described in the accompanying proxy statement:

Our board of directors has fixed the close of business on April 29, 2022 as the record date for the Annual Meeting. Only stockholders of record on April 29, 2022 are entitled to notice of and to vote at the Annual Meeting. Further information regarding voting rights and the matters to be voted upon is presented in the accompanying proxy statement. If you plan on attending the Annual Meeting as a stockholder, please follow the instructions on page 3 of the proxy statement.

IMPORTANT NOTICE REGARDING THE AVAILABILITY OF PROXY MATERIALS FOR THE STOCKHOLDERS MEETING TO BE HELD ON JUNE 24, 2022 – THE PROXY STATEMENT AND ANNUAL REPORT TO STOCKHOLDERS ARE AVAILABLE AT http://www.proxyvote.com. We are mailing a notice of availability over the Internet of the proxy materials which contains instructions on how to access our proxy materials on the Internet, as well as instructions on obtaining a paper copy.

Whether or not you plan to attend the Annual Meeting, we urge you to submit your vote via the Internet, telephone or mail.

We appreciate your continued support of A10 Networks, Inc. and look forward to either greeting you personally at the Annual Meeting or receiving your proxy.

This proxy statement and the form of proxy are furnished in connection with the solicitation of proxies by our board of directors for use at the 2022 Annual Meeting of stockholders of A10 Networks, Inc., a Delaware corporation (the “Company”), and any postponements, adjournments or continuations thereof (the “Annual Meeting”). The Annual Meeting will be held on Friday, June 24, 2022 at 10:00 a.m. Pacific Time, at 2300 Orchard Parkway, San Jose, California. The Notice of Internet Availability of Proxy Materials (the “Notice”) containing instructions on how to access this proxy statement and our annual report is first being mailed on or about May 11, 2022 to all stockholders entitled to vote at the Annual Meeting.

The information provided in the “question and answer” format below is for your convenience only and is merely a summary of the information contained in this proxy statement. You should read this entire proxy statement carefully. Information contained on, or that can be accessed through, our website is not intended to be incorporated by reference into this proxy statement and references to our website address in this proxy statement are inactive textual references only.

You will be voting on:

Our board of directors recommends a vote:

Holders of our common stock as of the close of business on April 29, 2022, the record date, may vote at the Annual Meeting. As of the record date, there were 75,824,501shares of our common stock outstanding. In deciding all matters at the Annual Meeting, each stockholder will be entitled to one vote for each share of our common stock held by them on the record date. We do not have cumulative voting rights for the election of directors.

Registered Stockholders. If shares of our common stock are registered directly in your name with our transfer agent, you are considered the stockholder of record with respect to those shares, and the Notice was provided to you directly by us. As the stockholder of record, you have the right to grant your voting proxy directly to the individuals listed on the proxy card or to vote in person at the Annual Meeting.

Street Name Stockholders. If shares of our common stock are held on your behalf in a stock brokerage account or by a bank or other nominee, you are considered the beneficial owner of those shares held in “street name,” and the Notice was forwarded to you by your broker or nominee, who is considered the stockholder of record with respect to those shares. As the beneficial owner, you have the right to direct your broker or nominee how to vote your shares. Beneficial owners are also invited to attend the Annual Meeting. However, since a beneficial owner is not the stockholder of record, you may not vote your shares of our common stock in person at the Annual Meeting unless you follow your broker’s procedures for obtaining a legal proxy. If you request a printed copy of our proxy materials by mail, your broker or nominee will provide a voting instruction card for you to use. Throughout this proxy, we refer to stockholders who hold their shares through a broker, bank or other nominee as “street name stockholders.”

A quorum is the minimum number of shares required to be present at the Annual Meeting for the Annual Meeting to be properly held under our amended and restated bylaws and Delaware law. The presence, in person or represented by proxy, of a majority of all issued and outstanding shares of our common stock entitled to vote at the Annual Meeting will constitute a quorum at the Annual Meeting. Abstentions, withhold votes and broker non-votes are counted as shares present and entitled to vote for purposes of determining a quorum.

If you are a stockholder of record, there are four ways to vote:

If you are a street name stockholder, you will receive voting instructions from your broker, bank or other nominee. You must follow the voting instructions provided by your broker, bank or other nominee in order to instruct your broker, bank or other nominee on how to vote your shares. Street name stockholders should generally be able to vote by returning an instruction card, or by telephone or on the Internet. However, the availability of telephone and Internet voting will depend on the voting process of your broker, bank or other nominee. As discussed above, if you are a street name stockholder, you may not vote your shares in person at the Annual Meeting unless you obtain a legal proxy from your broker, bank or other nominee.

Yes. If you are a stockholder of record, you can change your vote or revoke your proxy any time before the Annual Meeting by:

If you are a street name stockholder, your broker, bank or other nominee can provide you with instructions on how to change your vote.

To attend the meeting, you must be a holder of Company shares as of the record date of April 29, 2022. If you plan to attend, please notify the Company no later than June 23, 2022 at 5:00 p.m. Pacific Time by contacting Jaime Garcia (jgarcia@a10networks.com).

On the day of the meeting, you may be required to present a valid picture identification such as a driver’s license or passport and you may be denied admission if you do not. Please note that seating is limited. Use of cameras, recording devices, computers and other personal electronic devices will not be permitted at the Annual Meeting.

We intend to hold our Annual Meeting in person. However, we are actively monitoring the coronavirus (COVID-19) situation and are sensitive to the public health and travel concerns our stockholders may have and the protocols that federal, state, and local governments may impose. In the event it is not possible or advisable to hold our Annual Meeting in person, we will announce alternative arrangements for the meeting as promptly as practicable, which may include holding the meeting solely by means of remote communication. If we take this step, we will announce the decision to do so in advance by filing Definitive Additional Materials with the SEC along with notice of the change(s) to the Annual Meeting, and details on how to participate will be available at www.proxydocs.com and http://investors.a10networks.com.

Proxies are solicited by and on behalf of our board of directors. Dhrupad Trivedi, Brian Becker and Robert Cochran have been designated as proxies by our board of directors. When proxies are properly dated, executed and returned, the shares represented by such proxies will be voted at the Annual Meeting in accordance with the instructions of the stockholder. If no specific instructions are given, however, the shares will be voted in accordance with the recommendations of our board of directors as described above. If any matters not described in this proxy statement are properly presented at the Annual Meeting, the proxy holders will use their own judgment to determine how to vote the shares. If the Annual Meeting is adjourned, the proxy holders can vote the shares on the new Annual Meeting date as well, unless you have properly revoked your proxy instructions, as described above.

In accordance with the rules of the Securities and Exchange Commission (“SEC”), we have elected to provide our proxy materials, including this proxy statement and our annual report, primarily via the Internet. The Notice containing instructions on how to access our proxy materials is first being mailed on or about May 11, 2022 to all stockholders entitled to vote at the Annual Meeting. Stockholders may request to receive all future proxy materials in printed form by mail or electronically by email by following the instructions contained in the Notice. We encourage stockholders to take advantage of the availability of our proxy materials on the Internet to help reduce the environmental impact of our annual stockholder meetings. All stockholders who have previously requested to receive a paper copy of the materials, will receive a full set of paper proxy materials by U.S. mail.

Our board of directors, officers and other employees may be soliciting proxies for use at the Annual Meeting by personal interview, telephone, facsimile or electronic mail. No additional compensation will be paid to these persons for solicitation and all expenses associated with this solicitation will be borne by us. We will reimburse brokers or other nominees for reasonable expenses that they incur in sending our proxy materials to you if a broker or other nominee holds shares of our common stock on your behalf. At this time we have not engaged a proxy solicitor. If we do engage a proxy solicitor we will pay the customary costs associated with such engagement.

Brokerage firms and other intermediaries holding shares of our common stock in street name for customers are generally required to vote such shares in the manner directed by their customers. In the absence of timely directions, your broker will have discretion to vote your shares on our sole “routine” matter: the proposal to ratify the appointment of Armanino LLP. Your broker will not have discretion to vote on any other proposal absent direction from you.

We will announce preliminary voting results at the Annual Meeting. We will also disclose voting results on a Current Report on Form 8-K that we will file with the SEC within four business days after the Annual Meeting. If final voting results are not available to us in time to file a Current Report on Form 8-K within four business days after the Annual Meeting, we will file a Current Report on Form 8-K to publish preliminary results and will provide the final results in an amendment to such Current Report on Form 8-K as soon as they become available.

We have adopted an SEC-approved procedure called “householding,” which allows us to deliver a single copy of the Notice and, if applicable, our proxy materials to multiple stockholders who share the same address unless we have received contrary instructions from one or more of the stockholders. This procedure reduces our printing costs, mailing costs, and fees. Stockholders who participate in householding will continue to be able to access and receive separate proxy cards. Upon written or oral request, we will deliver promptly a separate copy of the Notice and, if applicable, our proxy materials to any stockholder at a shared address to which we delivered a single copy of any of these materials. To receive a separate copy or, if a stockholder is receiving multiple copies, to request that we only send a single copy of the Notice and, if applicable, our proxy materials, such stockholder may contact us at the following address:

Street name stockholders may contact their brokerage firm, bank, broker-dealer or other similar organization to request information about householding.

Stockholders may present proper proposals for inclusion in our proxy statement and for consideration at our next annual meeting of stockholders by submitting their proposals in writing to our Secretary in a timely manner. For a stockholder proposal to be considered at our 2023 annual meeting of stockholders, our Secretary must receive the written proposal at our principal executive offices prior to certain deadlines. Those deadlines vary based upon when we actually hold our 2023 annual meeting and also whether the stockholder intends the proposal to be included in our proxy statement for the meeting.

For a stockholder proposal to be considered for inclusion in our proxy statement for the 2023 annual meeting, our Secretary must receive the written proposal at our principal executive offices no later than January 11, 2023. In addition, stockholder proposals must comply with the requirements of SEC Rule 14a-8 regarding the inclusion of stockholder proposals in company-sponsored proxy materials. Stockholder proposals should be addressed to:

Our bylaws also establish an advance notice procedure for stockholders who wish to present a proposal at an annual meeting of stockholders but who do not intend for the proposal to be included in our proxy statement for the meeting. Our bylaws provide that the only business that may be conducted at an annual meeting is business that is (i) specified in our proxy materials with respect to such meeting, (ii) otherwise properly brought before the annual meeting by or at the direction of our board of directors, or (iii) properly brought before the annual meeting by a stockholder of record entitled to vote at the annual meeting who has delivered timely written notice to our Secretary, which notice must contain the information specified in the bylaws.

If we hold the 2023 annual meeting no more than 30 days before or after the one-year anniversary of this year’s Annual Meeting, then, for a stockholder proposal to be considered at the 2023 annual meeting, our Secretary must receive the written notice at our principal executive offices at the above address:

If we hold the 2023 annual meeting more than 30 days before or after the one-year anniversary of this year’s Annual Meeting, then our Secretary must receive the written notice no earlier than the close of business on the 120th day before the actual date of the 2023 annual meeting and no later than the close of business on the later of the following two dates:

If a stockholder who has notified us of his, her or its intention to present a proposal at an annual meeting does not appear at such annual meeting to present such proposal, we are not required to present the proposal for a vote at such annual meeting.

You may propose director candidates for consideration by our nominating and corporate governance committee. Any such recommendations should include the nominee’s name and qualifications for membership on our board of directors and should be directed to our Secretary at the address set forth above. For additional information regarding stockholder recommendations for director candidates, see “Board of Directors and Corporate Governance—Stockholder Recommendations for Nominations to the Board of Directors.”

In addition, our bylaws permit stockholders to nominate directors for election at an annual meeting of stockholders. To nominate a director, a stockholder must provide the information required by our bylaws and give timely notice to our Secretary in accordance with our bylaws, which, in general, require that the notice be received by our Secretary within the time period described above under “—Proposals Not Intended to be Included in our Proxy Statement.”

You may contact our Secretary at our principal executive offices for a copy of the relevant bylaw provisions regarding the requirements for making stockholder proposals and nominating director candidates.

Our business affairs are managed under the direction of our board of directors, which is currently composed of five members and has the following characteristics:

On April 26, 2021, director Mary Dotz notified our board of directors that she would not stand for re-election at the Annual Meeting. Following receipt of such notice, on April 26, 2021, our board of directors nominated Dana Wolf to stand for election to the Board at the Annual Meeting, to serve until the 2023 annual meeting of stockholders and until her successor is duly elected and qualified, subject to earlier resignation or removal. Four of the five individuals currently serving as directors are independent within the meaning of the listing standards of the New York Stock Exchange, as is nominee Dana Wolf.

The following table sets forth the names, ages and certain other information for each of our directors and director nominees as of May 11, 2022:

Dhrupad Trivedi joined A10 Networks in December 2019 as president and chief executive officer. Mr. Trivedi was also appointed as a member of our board of directors in December 2019 and as Chairperson of the board in September 2020. From March 2013 to November 2019, Dr. Trivedi served as President, Network Solutions – Industrial IT/IOT and Cybersecurity at Belden Inc., a manufacturer of networking, connectivity, and cable products, and also served as a corporate vice president from January 2010 to March 2013. Prior to this, he held multiple general management and corporate development roles at JDS Uniphase. Trivedi holds a Ph.D. in electrical engineering from University of Massachusetts, Amherst, a master’s degree in electrical engineering from University of Alabama and an MBA in finance from Duke University. Trivedi brings global leadership experience across multiple businesses and is passionate about driving leading technology businesses to win by creating value for customers.

Tor R. Braham has served as a member of our board of directors since March 2018. He is currently also a director of Viavi Solutions Inc., a network and service enablement and optical coatings company. Mr. Braham is also Of Counsel to the law firm of King, Holmes, Paterno and Soriano. He previously served as a member of the board of directors of Yahoo!, a provider of web services from April 2016 to June 2017, Altaba, Inc a publicly traded

investment company from June 2017 to December 2021, NetApp, Inc., a computer storage and data management company, from September 2013 to March 2016, Sigma Designs, Inc., an integrated circuit provider for the home entertainment market, from June 2014 to August 2016, Live Oak Acquisition Corp from February 2020 to December 2020, and Live Oak Acquisition Corp II, from December 2020 to October 2021. Mr. Braham served as Managing Director and Global Head of Technology Mergers and Acquisitions for Deutsche Bank Securities Inc., an investment bank, from 2004 until November 2012. From 2000 to 2004, he served as Managing Director and Co-Head of West Coast U.S. Technology, Mergers and Acquisitions for Credit Suisse First Boston, an investment bank. Prior to that role, Mr. Braham served as an investment banker with Warburg Dillon Read LLC and as an attorney at Wilson Sonsini Goodrich & Rosati. Mr. Braham has specific attributes that qualify him to serve as a member of our board of directors, including his extensive financial experience and knowledge of the technology industry gained through his service as an investment banker and lawyer to technology companies, as well as his service on public and private company boards.

Peter Y. Chung has served as a member of our board of directors since June 2013. Mr. Chung is a Managing Director and Chief Executive Officer of Summit Partners, L.P., where he has been employed since 1994. He is currently a director of MACOM Technology Solutions Holdings, Inc. as well as several privately-held companies. Mr. Chung previously served as a member of the board of directors of Acacia Communications. Mr. Chung has an M.B.A. from the Stanford University Graduate School of Business and an A.B. in Economics from Harvard University. Mr. Chung has specific attributes that qualify him to serve as a member of our board of directors, including his experience in investment banking, private equity and venture capital investing and in the communications technology sector, as well as his prior service on public and private company boards.

Eric Singer has served as a member of our board of directors since July 2019 and as our lead independent director since September 2021. Mr. Singer is a founder and Managing Member of VIEX Capital Advisors, a securities investment firm. In addition to a long track record as a successful investor in technology companies, Mr. Singer has substantial experience serving on public boards and in assisting them in creating and expanding shareholder value. Mr. Singer is currently a director of Immersion Corporation , a developer and licensor of touch feedback technology company, and previously served on the boards of directors of Quantum Corporation, a video data storage and management company, Numerex Corp., a provider of managed machine-to-machine enterprise solutions enabling the Internet of Things, RhythmOne plc and YuMe, Inc., each a provider of brand video advertising software and audience data, Support.com , Inc., a provider of tech support and support center services, Meru Networks, Inc., a Wi-Fi network solutions company, PLX Technology, Inc., a PCI Express and ethernet semiconductor company, and Sigma Designs, Inc., an integrated circuit provider for the home entertainment market, among other companies. Mr. Singer has a B.A. from Brandeis University. Mr. Singer has specific attributes that qualify him to serve as a member of our board of directors, including his extensive financial and operating experience and knowledge of the technology industry gained through his service on numerous public company boards.

Dana Wolf is an entrepreneur in the security space. From August 2017 to November 2021 she served as Senior Vice President of Product & Marketing at Fastly Inc., a global edge cloud network provider. From August 2013 to August 2017, she was the Head of Product for the cloud security product lines at OpenDNS, Inc. (acquired by Cisco Systems, Inc.), a company providing domain name system resolution services. Ms. Wolf has over 18 years of experience in the security space, holding both product and engineering leadership roles at both Rapid7, Inc., a cyber security analytics and automation services company, and RSA Security LLC, a computer and network security company with a focus on protecting and managing online identities and digital assets. Ms. Wolf holds a B.A. from Lawrence University in Mathematics, Computer Science and Theatre and an M.B.A. (High Tech) from Northeastern University. Ms. Wolf has specific attributes that qualify her to serve as a member of our board of directors, including her extensive experience in the cyber security industry and cloud-based businesses.

Our common stock is listed on the New York Stock Exchange. Under the listing standards of the New York Stock Exchange, independent directors must comprise a majority of a listed company’s board of directors. In addition, the listing standards of the New York Stock Exchange require that, subject to specified exceptions, each member of a listed company’s audit, compensation, and nominating and corporate governance committees be independent. Under the listing standards of the New York Stock Exchange, a director will only qualify as an “independent director” if, in the opinion of that listed company’s board of directors, that director does not have a relationship that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director.

Audit committee members must also satisfy the independence criteria set forth in Rule 10A-3 under the Securities Exchange Act of 1934, as amended (the “Exchange Act”), and the listing standards of the New York Stock Exchange. In addition, compensation committee members must also satisfy the independence criteria set forth under the listing standards of the New York Stock Exchange.

Our board of directors has undertaken a review of the independence of each director. Based on information provided by each director concerning his background, employment and affiliations, our board of directors has determined that all of our directors other than Mr. Trivedi, our chief executive officer, are “independent” as that term is defined under the listing standards of the New York Stock Exchange and do not have any relationships that would interfere with the exercise of independent judgment in carrying out the responsibilities of a director. In making these determinations, our board of directors considered the current and prior relationships that each director has with our company and all other facts and circumstances our board of directors deemed relevant in determining their independence, including the beneficial ownership of our capital stock by each non-employee director, and the transactions involving them described in the section titled “Related Person Transactions.”

The Board is committed to strong, independent Board leadership and oversight of management’s performance. In addition to having substantially all of its members be independent under applicable listing standards and SEC standards, our current Board includes an affiliate from our largest stockholder as of March 31, 2022. The Board believes that whether to have the same person occupy the offices of Chairperson of the Board and Chief Executive Officer should be decided by the Board, from time to time, in its business judgment after considering relevant factors, including the specific needs of the business and what is in the best interests of our stockholders. If the Chairperson is an employee, the Board may appoint a lead independent director to help ensure robust independent leadership on the Board.

The Chairperson of the Board has the powers and duties customarily and usually associated with the office of the chairperson of the board, including setting the schedule and agenda for Board meetings and presiding at meetings of the Board and meetings of our stockholders, unless a Chairperson of a stockholder meeting is otherwise appointed by the Board. The Chairperson also has the authority to call special meetings of our stockholders. If our Chairperson is an independent, non-employee director, the Chairperson has the responsibilities of the lead independent director.

Mr. Trivedi currently serves as both Chairperson of our board of directors and our Chief Executive Officer. Our board believes that the current board leadership structure provides effective independent oversight of management while allowing our board and management to benefit from Mr. Trivedi’s leadership and years of experience as an executive in multiple global high technology industries including networking, cloud, IOT and cybersecurity. Mr. Trivedi is best positioned to identify strategic priorities, lead critical discussion and execute our strategy and business plans. Mr. Trivedi possesses detailed in-depth knowledge of the issues, opportunities, and challenges facing our company.

Our lead independent director has the responsibility to schedule and prepare agendas for meetings of the outside directors. The lead independent director may communicate with our Chief Executive Officer, disseminate information to the rest of the Board in a timely manner, raise issues with management on behalf of the outside directors when appropriate, and facilitate communications between management and the outside directors. In addition, the lead independent director may have other responsibilities, including calling meetings of outside directors when necessary and appropriate, being available, when appropriate, for consultation and direct communication with our stockholders, building a productive relationship between the Board and the Chief Executive Officer, ensuring the Board fulfills its oversight responsibilities in our strategy, risk oversight and succession planning, and performing such other duties as the Board may from time to time designate.

Mr. Singer serves as our lead independent director. In this role, Mr. Singer presides over periodic meetings of our independent directors, serves as a liaison between our chairperson of the board of directors and the independent directors, and performs such additional duties as our board of directors may otherwise determine and delegate.

During our fiscal year ended December 31, 2021, the board of directors held five (5) meetings (including regularly scheduled and special meetings) and acted by written consent four (4) times. Throughout the year, directors met frequently to discuss our operations, the impact of Covid-19 on our business, strategic matters and other business.

In many instances, these meetings resulted in formal board action approved by unanimous written consent. In other instances, these meetings resulted in our board of directors providing input to our management team throughout the year. No director attended fewer than 75% of the aggregate of (i) the total number of meetings of our board of directors held during the period for which he or she has been a director and (ii) the total number of meetings held by all committees of our board of directors on which he or she served during the periods that he or she served.

Although we do not have a formal policy regarding attendance by members of our board of directors at annual meetings of stockholders, we encourage, but do not require, our directors to attend. All five of our directors attended our 2021 annual meeting of stockholders. Our board of directors has established three standing committees: an audit committee, a compensation committee and a nominating and corporate governance committee. The composition and responsibilities of each of these committees is described below. Members will serve on these committees until their resignation or until as otherwise determined by our board of directors.

The audit committee is currently comprised of Messrs. Braham, Chung and Ms. Dotz. Ms. Dotz is currently the chair of the audit committee. Our board of directors has determined that each of the members of this committee satisfies the requirements for independence and financial literacy under the applicable rules and regulations of the New York Stock Exchange and the SEC. Our board of directors has also determined that Mr. Chung and Ms. Dotz each qualify as an “audit committee financial expert” as defined in the SEC rules and each satisfy the financial sophistication requirements of the New York Stock Exchange.

The audit committee is responsible for, among other things:

The audit committee operates under a written charter that satisfies the applicable standards of the SEC and the New York Stock Exchange. A copy of the charter of the audit committee is available on our website at http://investors.a10networks.com. During 2021, the audit committee held four (4) meetings and acted by written consent one (1) time.

The compensation committee currently consists of Messrs. Braham, Chung, and Singer. Mr. Chung is the chair of the compensation committee. Our board of directors has determined that each member of this committee is independent under the applicable rules and regulations of the New York Stock Exchange and the SEC, a non-employee director, as defined pursuant to Rule 16b-3 promulgated under the Exchange Act, and an outside director, as defined under Section 162(m) of the Internal Revenue Code of 1986, as amended.

The compensation committee is responsible for, among other things:

The compensation committee operates under a written charter that satisfies the applicable rules and regulations of the SEC and the listing standards of the New York Stock Exchange. A copy of the charter of the compensation committee is available on our website at http://investors.a10networks.com. During 2021, the compensation committee held four (4) meetings and acted by written consent eight (8) times.

The nominating and corporate governance committee currently consists of Messrs. Chung, and Singer. Mr. Singer is the chair of the nominating and corporate governance committee. Our board of directors has determined that each member of this committee meets the requirements for independence under the rules of the New York Stock Exchange.

The nominating and corporate governance committee is responsible for, among other things:

The nominating and corporate governance committee operates under a written charter that satisfies the applicable listing standards of the New York Stock Exchange. A copy of the charter of the nominating and corporate governance committee is available on our website at http://investors.a10networks.com. During 2021, the nominating and corporate governance committee held three (3) meetings and acted by written consent one (1) time.

Messrs. Braham, Chung and Singer are the current members of our compensation committee. None of the members of our compensation committee is or has been one of our officers or employees. None of our executive officers currently serves, or in the past year has served, as a member of the compensation committee or director (or other board committee performing equivalent functions or, in the absence of any such committee, the entire board of directors) of any entity that has one or more executive officers serving on our compensation committee or our board of directors.

Our nominating and corporate governance committee uses a variety of methods for identifying and evaluating director nominees. In its evaluation of director candidates, our nominating and corporate governance committee will consider the current size and composition of our board of directors and the needs of our board of directors and the respective committees of our board of directors. Some of the qualifications that our nominating and corporate governance committee considers include, without limitation, issues of character, integrity, judgment, diversity (including, but not limited to, diversity of gender, ethnicity, race, international background and life experience), independence, area of expertise, corporate experience, length of service, potential conflicts of interest and other commitments. Nominees must also have the ability to offer advice and guidance to our Chief Executive Officer based on past experience in positions with a high degree of responsibility and be leaders in the companies or institutions with which they are affiliated. Director candidates must have sufficient time available in the judgment of our nominating and corporate governance committee to perform all board of director and committee responsibilities. Members of our board of directors are expected to prepare for, attend, and participate in all board of director and applicable committee meetings. Other than the foregoing, there are no stated minimum criteria for director nominees, although our nominating and corporate governance committee may also consider such other factors as it may deem, from time to time, are in our and our stockholders’ best interests.

Although our board of directors does not maintain a specific policy with respect to board diversity, our board of directors believes that our board should be a diverse body, and our nominating and corporate governance committee considers a broad range of backgrounds and experiences. In making determinations regarding nominations of directors, our nominating and corporate governance committee may take into account the benefits of diverse viewpoints. Our nominating and corporate governance committee also considers these and other factors as it oversees the annual board of director and committee evaluations. After completing its review and evaluation of director candidates, our nominating and corporate governance committee recommends to our full board of directors the director nominees for selection. The Company is committed to diversity at all levels, including with our directors, and our nominating and corporate governance committee is committed to considering diversity, including gender diversity, in identifying future candidates for nomination to the board. Sixty percent of our directors self-identify as being from one or multiple diverse groups.

Our nominating and corporate governance committee will consider candidates for director recommended by stockholders so long as such recommendations comply with our amended and restated certificate of incorporation currently in effect and amended and restated bylaws and applicable laws, rules and regulations, including those promulgated by the SEC. The nominating and corporate governance committee will evaluate such recommendations in accordance with its charter, our amended and restated bylaws, our policies and procedures for director candidates, as well as the regular director nominee criteria described above. This process is designed to ensure that our board of directors includes members with diverse backgrounds, skills and experience, including appropriate financial and other expertise relevant to our business. Eligible stockholders wishing to recommend a candidate for nomination should contact our Secretary in writing. Such recommendations must include, amongst other things provided in our Bylaws, information about the candidate, evidence of the recommending stockholder’s ownership of our common stock and a signed letter from the candidate confirming willingness to serve on our board of directors. Our nominating and corporate governance committee has discretion to decide which individuals to recommend for nomination as directors.

Any nomination should be sent in writing to our Secretary at A10 Networks, Inc., 2300 Orchard Parkway, San Jose, CA 95131. If we hold the 2023 annual meeting of stockholders no more than 30 days before or after the one-year anniversary of this year’s Annual Meeting, then our Secretary must receive the written nomination;

If we hold the 2023 annual meeting more than 30 days before or after the one-year anniversary of this year’s Annual Meeting, then our Secretary must receive the written nomination no earlier than the close of business on the 120th day before the actual date of the 2023 annual meeting and no later than the close of business on the later of the following two dates:

Interested parties wishing to communicate with our board of directors or with an individual member or members of our board of directors may do so by writing to our board of directors or to the particular member or members of our board of directors, and mailing the correspondence to our General Counsel at A10 Networks, Inc., 2300 Orchard Parkway, San Jose, CA 95131, Attn: General Counsel. Each communication should set forth (i) the name and address of the stockholder, as it appears on our books, and if the shares of our common stock are held by a nominee, the name and address of the beneficial owner of such shares, and (ii) the number of shares of our common stock that are owned of record by the record holder and beneficially by the beneficial owner.

Our General Counsel, in consultation with appropriate members of our board of directors as necessary, will review all incoming communications and, if appropriate, forward such communications to the member or members of our board of directors to whom such communications were directed, or if none is specified, to the Chairperson of our board of directors.

Our board of directors has adopted Corporate Governance Guidelines that address items such as the qualifications and responsibilities of our directors and director candidates and corporate governance policies and standards applicable to us in general. In addition, our board of directors has adopted a Code of Business Conduct and Ethics that applies to all of our employees, officers and directors, including our Chief Executive Officer, Chief Financial Officer, and other executive and senior financial officers. The full text of our Corporate Governance Guidelines and our Code of Business Conduct and Ethics is posted on the Corporate Governance portion of our website under Governance Documents at http://investors.a10networks.com. We will post amendments to our Code of Business Conduct and Ethics or waivers of our Code of Business Conduct and Ethics for directors and executive officers on the same website.

Pursuant to our Insider Trading Policy, all employees (including directors) are prohibited from engaging in transactions in publicly traded options and other derivative securities with respect to our common stock, including any hedging or similar transaction designed to decrease the risks associated with holding company securities. Our directors and named executive officers are also prohibited from pledging company securities as collateral or holding company securities in a margin account.

Risk is inherent with every business, and we face a number of risks, including strategic, financial, business and operational, legal and compliance, and reputational. We have designed and implemented processes to manage risk in our operations. Management is responsible for the day-to-day management of risks the company faces, while our board of directors, as a whole and assisted by its committees, has responsibility for the oversight of risk management. In its risk oversight role, our board of directors has the responsibility to satisfy itself that the risk management processes designed and implemented by management are appropriate and functioning as designed.

Our board of directors believes that open communication between management and our board of directors is essential for effective risk management and oversight. Our board of directors meets with our Chief Executive Officer and other members of the senior management team at quarterly meetings of our board of directors, where, among other topics, they discuss strategy and risks facing the company, as well as at such other times as they deemed appropriate.

While our board of directors is ultimately responsible for risk oversight, our board committees assist our board of directors in fulfilling its oversight responsibilities in certain areas of risk. Our audit committee assists our board of directors in fulfilling its oversight responsibilities with respect to risk management in the areas of internal control over financial reporting, disclosure controls and procedures, legal and regulatory compliance and cybersecurity, and discusses with management and the independent auditor guidelines and policies with respect to risk assessment and risk management. Our audit committee also reviews our major financial risk exposures and the steps management has taken to monitor and control these exposures. Our audit committee also monitors certain key risks on a regular basis throughout the fiscal year, such as risks associated with internal control over financial reporting and liquidity risk. Our nominating and corporate governance committee assists our board of directors in fulfilling its oversight responsibilities with respect to the management of risk associated with board organization, membership and structure, and corporate governance. Our compensation committee assesses risks created by the incentives inherent in our compensation policies. Finally, our full board of directors reviews strategic and operational risk in the context of reports from the management team, receives reports on all significant committee activities at each regular meeting, and evaluates the risks inherent in significant transactions.

A10 is committed to providing networking solutions that enable next-generation networks focused on reliability, availability, scalability and cybersecurity. As cyber-attacks increase in volume and complexity, we integrate security as a key attribute in our solutions that further enable our customers to continue to adapt to market trends in cloud, internet of things and the ever increasing need for more data, building upon our strong global footprint and leadership in application and network infrastructure. Our board of directors is responsible for overseeing cybersecurity and data protection strategy. Management regularly reports any risk exposure to the Board as well as the steps taken to monitor and control them.

We are committed to maintaining the highest standards of ethics and corporate governance, to fostering a diverse and inclusive workforce, and to reducing our environmental impact. We believe these practices will deliver the highest value for our employees, customers, partners and shareholders. For this reason, we have an ESG policy to ensure that our Company is working towards continuing to a sustainable future in the following areas:

We are committed to business practices that preserve the environment upon which our society and economy depend. We are committed to meeting or exceeding all legal and compliance guidelines for our people, products, and operations. In addition, we strive to deliver products and services that minimize the impact to the environment throughout our value chain.

We believe in fostering a diverse and inclusive environment for employees, as well as encouraging diversity and inclusion within the customer and partner ecosystem, and our community at large. We strive to create a corporate culture that values diverse backgrounds and innovative thinking.

We are committed to building strong corporate governance guidelines based on best practices, changing requirements, and feedback from employees, customers, partners, vendors and shareholders.

Each non-employee director who first joins our board of directors will be granted an initial equity award with a value of $225,000. On the date of each annual meeting of stockholders, each continuing non-employee director will be granted an annual equity award with a value of $150,000. However, a continuing non-employee director who, as of the date of our annual stockholder meeting, has not served as a board member for the entire 12-month period prior to the annual stockholder meeting will receive an annual award with a value that is prorated based on the number of months the director served during the prior year. The initial and annual equity awards will be granted in the form of restricted stock units, and the number of shares to be granted pursuant to such equity awards will be determined by the closing price of a share of our common stock on the New York Stock Exchange on the grant date. A non-employee director who is not continuing as a director following an annual stockholder meeting will not receive an annual equity award at such meeting.

The initial equity award will be scheduled to vest in three, equal, annual installments from the date the non-employee director joins our board of directors, subject to continued service with us through each such date. Each annual equity award will vest as to 100% of the underlying shares on the earlier of the one-year anniversary of the award’s grant date or the date of our next annual stockholder meeting, subject to continued service with us through such date.

Our board of directors approved the following annual compensation package for our non-employee directors:

The following table provides information regarding the total compensation that was paid by the Company to each of our non-employee directors in 2021. None of our non-employee directors were granted option awards in 2021.

Our board of directors is currently composed of five members. On April 26, 2021, director Mary Dotz notified our board of directors that she would not stand for re-election at the Annual Meeting. Following receipt of such notice, on April 26, 2021, our board of directors nominated Dana Wolf to stand for election to the Board at the Annual Meeting. At the Annual Meeting, each of the five recommended nominees, if elected, will serve for a one-year term. Each director’s term continues until the election and qualification of his or her successor, or such director’s earlier death, resignation, or removal.

As recommended by the nominating and corporate governance committee, the board’s nominees for election to the board are the following current members of the board: Tor R. Braham, Peter Y. Chung, Eric Singer, Dhrupad Trivedi and Dana Wolf. If elected, each nominee would hold office until the annual meeting to be held in 2023 and until their successor is elected and qualified or until their earlier death, resignation or removal. For information concerning the nominee, please see the section titled “Board of Directors and Corporate Governance.”

If you are a stockholder of record and you sign your proxy card or vote by telephone or over the Internet but do not give instructions with respect to the voting of directors, your shares will be voted “FOR” the election of the nominees listed above. Each nominee has advised us that they are willing to serve on our board of directors, if elected; however, in the event that a director nominee is unable or declines to serve as a director at the time of the Annual Meeting, the proxies will be voted for any nominee who shall be designated by our board of directors to fill such vacancy. If you are a street name stockholder and you do not give voting instructions to your broker or nominee, your broker will leave your shares unvoted on this matter.

The election of each director requires a plurality vote of the shares of our common stock present in person or by proxy at the Annual Meeting and entitled to vote thereon to be approved. Broker non-votes will have no effect on this proposal.

The Dodd-Frank Wall Street Reform and Consumer Protection Act of 2010, or the Dodd-Frank Act, requires us to obtain an advisory vote (non-binding) from our stockholders on the compensation of our named executive officers as disclosed pursuant to Section 14A of the Exchange Act. This proposal, commonly known as a “Say-on-Pay” proposal, gives our stockholders the opportunity to express their views on our named executive officers’ compensation as a whole. This vote is not intended to address any specific item of compensation or any specific named executive officer, but rather the overall compensation of all of our named executive officers and the philosophy, policies and practices described in this proxy statement.

The Say-on-Pay vote is advisory, and therefore is not binding on us, the compensation committee or our board of directors. However, the Say-on-Pay vote will provide information to us regarding investor sentiment about our executive compensation philosophy, policies and practices, which the compensation committee will be able to consider when determining executive compensation for the remainder of the current fiscal year and beyond. Our board of directors and our compensation committee value the opinions of our stockholders and to the extent there is any significant vote against the named executive officer compensation as disclosed in this proxy statement, we will endeavor to communicate with stockholders to better understand the concerns that influenced the vote, consider our stockholders’ concerns and the compensation committee will evaluate whether any actions are necessary to address those concerns.

We believe that the information provided in the “Executive Compensation” section of this proxy statement, and in particular the information discussed in “Executive Compensation—Compensation Discussion and Analysis” beginning on page 23 below, demonstrates that our executive compensation program was designed appropriately and is working to ensure management’s interests are aligned with our stockholders’ interests to support long-term value creation. Accordingly, we ask our stockholders to vote “FOR” the following resolution at the Annual Meeting:

“RESOLVED, that the stockholders approve, on an advisory basis, the compensation paid to the named executive officers, as disclosed in the proxy statement for the 2022 Annual Meeting pursuant to Item 402 of Regulation S-K and other compensation disclosure rules of the SEC, including the compensation discussion and analysis, compensation tables and narrative discussion, and other related disclosure.”

The approval, on an advisory and non-binding basis, of the compensation of our named executive officers as described in this proxy statement requires the affirmative vote of a majority of the shares present in person or represented by proxy at the Annual Meeting and entitled to vote on this proposal. Abstentions are considered as a vote “against” the proposal because an abstention represents a share entitled to vote on this proposal. Broker non-votes will have no effect on the outcome of this proposal. You may vote “for,” “against” or abstain” on this proposal.

The audit committee of the board of directors has appointed Armanino LLP (“Armanino”), an independent registered public accounting firm, to audit our consolidated financial statements for our fiscal year ending December 31, 2022. Armanino has served as our independent registered public accounting firm since September 2019 and audited our consolidated financial statements for our fiscal year ended December 31, 2019, 2020 and 2021. Representatives of Armanino will be present at the Annual Meeting, and they will have an opportunity to make a statement and will be available to respond to appropriate questions from our stockholders.

At the Annual Meeting, our stockholders are being asked to ratify the appointment of Armanino as our independent registered public accounting firm for our fiscal year ending December 31, 2022. The audit committee is submitting the appointment of Armanino to our stockholders because we value our stockholders’ views on our independent registered public accounting firm and as a matter of good corporate governance. If our stockholders do not ratify the appointment of Armanino, our board of directors may reconsider the appointment.

Notwithstanding the appointment of Armanino and even if our stockholders ratify the appointment, the audit committee, in its discretion, may appoint another independent registered public accounting firm at any time during our fiscal year if the audit committee believes that such a change would be in the best interests of the Company and its stockholders.

The following table presents fees for professional audit services and other services rendered to the Company by Armanino for our fiscal year ended December 31, 2021 and 2020.

In our fiscal year ended December 31, 2021, there were no other professional services provided by Armanino, other than those listed above, that would have required the audit committee to consider their compatibility with maintaining the independence of Armanino.

The audit committee has established a policy governing our use of the services of our independent registered public accounting firm. Under the policy, the audit committee is required to pre-approve all audit and non-audit services performed by our independent registered public accounting firm in order to ensure that the provision of such services does not impair the public accountants’ independence. All fees paid to Armanino for our fiscal year ended December 31, 2021 and 2020 were pre-approved by the audit committee.

The ratification of the appointment of Armanino requires the affirmative vote of a majority of the shares of our common stock present in person or by proxy at the Annual Meeting and entitled to vote thereon. Abstentions will have the effect of a vote AGAINST the proposal and broker non-votes will have no effect.

The audit committee is a committee of the board of directors comprised solely of independent directors as required by the listing standards of the New York Stock Exchange and rules and regulations of the SEC. The audit committee operates under a written charter approved by the board of directors, which is available on our website at http://investors.a10networks.com. The composition of the audit committee, the attributes of its members and the responsibilities of the audit committee, as reflected in its charter, are intended to be in accordance with applicable requirements for corporate audit committees. The audit committee reviews and assesses the adequacy of its charter and the audit committee’s performance on an annual basis.

With respect to our financial reporting process, our management is responsible for (1) establishing and maintaining internal controls and (2) preparing our consolidated financial statements. Our independent registered public accounting firm is responsible for auditing these financial statements. It is the responsibility of the audit committee to oversee these activities. It is not the responsibility of the audit committee to prepare our financial statements. These are the fundamental responsibilities of management. In the performance of its oversight function, the audit committee has:

Based on the audit committee’s review and discussions with management and Armanino, the audit committee recommended to the board of directors that the audited financial statements be included in our Annual Report on Form 10-K for the fiscal year ended December 31, 2021 for filing with the Securities and Exchange Commission.

Respectfully submitted by the members of the audit committee of the board of directors:

This report of the audit committee is required by the SEC and, in accordance with the SEC’s rules, will not be deemed to be part of or incorporated by reference by any general statement incorporating by reference this proxy statement into any filing under the Securities Act of 1933, as amended (“Securities Act”), or under the Exchange Act, except to the extent that we specifically incorporate this information by reference, and will not otherwise be deemed “soliciting material” or “filed” under either the Securities Act or the Exchange Act.

The following table identifies certain information about our executive officers as of May 11, 2022. Officers are elected by our board of directors to hold office until their successors are elected and qualified. There are no family relationships among any of our directors or executive officers.

Dhrupad Trivedi is also a director of our company. Please see the section titled “Board of Directors and Corporate Governance” for his background and experience.

Brian Becker has served as our Chief Financial Officer since February 2021. He was appointed Interim Chief Financial Officer in September 2020 and served as Vice President and Corporate Controller from January 2018 until such appointment. Prior to joining our company, Mr. Becker served as Vice President, Accounting and Corporate Controller for YuMe, Inc., a provider of brand video advertising software and audience data, from June 2014 to December 2017, and as Director, Revenue and Cost Accounting, from August 2013 to June 2014. He also served in various roles within Revenue Accounting at Symantec Corporation, a cybersecurity software and services company, from 2010 through 2012. Mr. Becker began his career in public accounting at Ernst & Young, LLP in San Jose, California. Mr. Becker is a certified public accountant licensed by the California Board of Accountancy and holds a B.A. in Business Economics from the University of California, Santa Barbara.

Matt Bruening has served as our Executive Vice President, Worldwide Sales and Marketing since January 2021, and, prior to that, served as our Executive Vice President, Worldwide Sales since April 2020. Mr. Bruening was previously Senior Vice President of Sales at Endgame, an endpoint security company since September 2017. Prior to Endgame, from July 2009 to June 2017 he served as Vice President, Enterprise Security Sales/ Americas at SecureWorks Corporation, an internet security company. From 2001-2004, Mr. Bruening was Vice President, Global Sales at Applied Innovation, a publicly traded company delivering network management solutions to major service providers. Mr. Bruening is a graduate of John Carroll University and holds numerous executive and sales leadership certifications.

Robert Cochran has served as our Executive Vice President, Legal and Corporate Collaboration since November 2016, our Chief Risk Compliance Officer since October 2016 and Secretary since August 2004. He previously served as our Vice President, Legal and Corporate Collaboration from January 2012 to November 2016 and as a member of our board of directors from April 2012 to November 2018. Mr. Cochran currently serves as a director of Techpoint, Inc., a fabless semiconductor company that designs, markets, and sells mixed-signal integrated circuits for HD video applications in the security surveillance and automotive markets. From January 1993 to January 2012, Mr. Cochran was an attorney in private practice in Woodside, California, where he had served as our outside legal counsel since our incorporation until he joined us in 2012. From 2004 to 2010, Mr. Cochran served as a director of Techwell, Inc., a fabless semiconductor company that designed, marketed, and sold mixed-signal integrated circuits. Mr. Cochran has a J.D. from Harvard Law School and an A.B. in Economics from Harvard University.

This Compensation Discussion and Analysis provides an overview of the material components of our executive compensation program. The following persons are collectively referred to in this Compensation Discussion and Analysis and the accompanying compensation tables as our “named executive officers”:

Our products and services address networking and security technology requirements. We are well positioned to help our customers address the emerging themes of an increasingly complex cybersecurity landscape and new technology to support changing consumption trends. We have navigated challenges related to the pandemic and associated economic disruptions and have positioned A10 Networks for consistent organic growth and increased profitability. Our business philosophy is to build long-term value and we are committed to drive growth and improve profitability. Our executive compensation philosophy is focused on real pay delivery through revenue and operating margin growth that drives total shareholder return (“TSR”) and aligns employees with customers and stockholders.

Our 2021 fiscal year was a year focused on driving growth and profitability with consistent operational excellence and execution amidst a challenging environment. Our compensation decisions were consistent with our financial performance, including the following:

Based on the foregoing, we believe our increase in NEO compensation is in line with our improved financial and stock performance.

We are committed to sound executive compensation policies and practices, as highlighted in the following table.

In 2021, our say-on-pay proposal passed by 81%. As a result, we made no changes to our compensation philosophy or programs.

We compensate for achievement of short-term and long-term financial and operating goals and have reasonable base salaries, limited perquisites, and no pensions or gross-up payments. Our compensation program is designed to attract and retain the best available personnel for positions of substantial responsibility, provide incentives for such persons to perform to the best of their abilities, and to promote the success of our business.

The following table identifies the main elements of our executive compensation program and the rationale for each:

The following sections describe each component of our executive compensation program, provide the rationale for each component, and explain how the compensation amounts and awards were determined for 2021.

Base salary is the primary fixed component of our named executive officers’ compensation. We use base salary to compensate our named executive officers for services rendered during the fiscal year and to ensure that we remain competitive in attracting and retaining executive talent. We typically review and consider adjustments to our named executive officers’ base salaries on an annual basis, and consistent with such practice, to remain competitive Mr. Trivedi’s annual base salary was increased from $600,000 in 2021 to $650,000 effective February 1, 2022, Mr. Bruening’s annual base salary was increased from $320,000 in 2021 to $340,000 effective February 1, 2022 and Mr. Becker’s annual base salary was increased from $300,000 in 2021 to $310,000 effective in February 1, 2022. Mr. Cochran’s annual base salary was not increased in 2022.

In March 2014, our board of directors adopted an Executive Incentive Compensation Plan, referred to as our Bonus Plan. Our Bonus Plan allows our compensation committee to provide cash incentive awards to selected employees, including our named executive officers, based upon performance goals established by our compensation committee.

Under the Bonus Plan, our compensation committee determines the performance goals applicable to awards, which goals may include, without limitation: attainment of research and development milestones, sales bookings, business divestitures and acquisitions, cash flow, cash position, earnings (which may include any calculation of earnings, including but not limited to earnings before interest and taxes, earnings before taxes, earnings before interest, taxes, depreciation and amortization and net earnings), earnings per share, net income, net profit, net sales, operating cash flow, operating expenses, operating income, operating margin, overhead or other expense reduction, product defect measures, product release timelines, productivity, profit, return on assets, return on capital, return on equity, return on investment, return on sales, revenue, revenue growth, sales results, sales growth, stock price, time to market, total stockholder return, working capital, and individual objectives such as peer reviews or other subjective or objective criteria. Performance goals that include the Company’s financial results may be determined in accordance with U.S. generally accepted accounting principles, or GAAP, or such financial results may consist of non-GAAP financial measures and any actual results may be adjusted by our compensation committee for one-time items or unbudgeted or unexpected items when determining whether the performance goals have been met. The goals may be on the basis of any factors our compensation committee determines relevant, and may be adjusted on an individual, divisional, business unit or company-wide basis. Any criteria used may be measured on such basis as our compensation committee determines. The performance goals may differ from participant to participant and from award to award.

Our compensation committee may, in its sole discretion and at any time, increase, reduce or eliminate a participant’s actual award, and/or increase, reduce or eliminate the amount allocated to the bonus pool for a performance period. The actual award may be below, at or above a participant’s target award, in our compensation committee’s discretion. Our compensation committee may determine the amount of any reduction on the basis of such factors as it deems relevant, and it is not required to establish any allocation or weighting with respect to the factors it considers.

Actual awards are paid in cash (or its equivalent) in a single lump sum only after they are earned and approved by our compensation committee. Unless otherwise determined by our compensation committee, to earn an actual award, a participant must be employed by the Company (or an affiliate of the Company) through the date the bonus is paid. Payment of bonuses occurs as soon as administratively practicable after they are earned, but no later than the dates set forth in the Bonus Plan.

Our board of directors has the authority to amend, alter, suspend or terminate the Bonus Plan provided such action does not alter or impair the existing rights of any participant with respect to any earned bonus.

For 2021, Messrs. Trivedi, Becker, Bruening and Cochran were eligible to receive annual cash bonuses based 100% on corporate performance goals under our 2021 Executive Cash Incentive Plan (the “Cash Incentive Plan”), as approved by our compensation committee. The Cash Incentive Plan was established under and subject to the terms

of our Executive Incentive Compensation Plan. The corporate performance goal under the Cash Incentive Plan was based on achievement of two financial measures, 1) revenue with a 70% weighting and 2) adjusted net earnings before interest, taxes, depreciation and amortization (“net EBITDA”) with a 30% weighting, which is a non-GAAP measure^[1]. Generally, the portion of the corporate performance based on the revenue would result in funding of bonuses at 60% upon the achievement of a minimum threshold level of revenue of $234 million, 100% upon the achievement of a target level of revenue of $239 million and a maximum capped at140% upon the achievement of $249 million, as specified in the Cash Incentive Plan. The portion of the corporate performance goal based on adjusted net EBITDA would result in funding of bonuses at 60% upon the achievement of a threshold level of adjusted net EBITDA of $52.6 million, 100% upon the achievement of a target level of adjusted net EBITDA of $54.6 million and a maximum of 140% upon the achievement of net EBITDA of $59.6 million. Mr. Trivedi’s and Mr. Bruening’s target bonus opportunity for our 2021 fiscal year was equal to 100% of their 2021 base salary and Mr. Becker’s and Mr. Cochran’s target bonus opportunity for our 2021 fiscal year was equal to 50% of their 2021 base salary, in each case subject to proration for the amount of time they served in their roles. Our 2021 financial goals are based on our operating plan approved by our board of directors, are in line with analysts estimates, and exceeded our 2020 financial results.

In early 2022, our compensation committee reviewed our achievement against our corporate performance goals. Based on 2021 revenue of $250 million (a $24.5 million, or 10.9 percent, improvement year-over-year) and adjusted net EBITDA of $62.4 million (a $16.8 million, or 36.9 percent, improvement year-over-year), the compensation committee determined a bonus payout at 140% of target for each performance goal. Accordingly, the bonuses were earned pursuant to the corporate performance goals under the Cash Incentive Plan were equal to: $840,000 for Mr. Trivedi, $210,000 for Mr. Becker, $448,000 for Mr. Bruening, and $211,220 for Mr. Cochran.

In February of 2021,our compensation committee approved the grant to certain of our named executive officers of time-based restricted stock unit awards (“RSUs”) covering the following number of shares of our common stock and the grant of performance-based restricted stock unit awards (“PSUs”) covering the following target number of shares of our common stock:

The PSUs comprised 70% of the annual equity awards to each of the above-named executive officers and include both performance-based vesting and service-based vesting. The PSUs will become eligible to vest upon the achievement of certain stock price targets as set forth below (the “Performance Milestones”), as well as continued service to the Company, with vesting of any portion for which the Performance Milestone is achieved (an “Eligible Portion”) to be scheduled to occur in three equal installments, with the first one-third (1/3rd) of the Eligible Portion to vest within thirty (30) days of achievement of the Performance Milestone and one-third (1/3) of the Eligible Portion to vest on each of the first and second anniversaries of achievement of the Performance Milestone, subject in each case to continued service on each such date.

The RSUs comprised the remaining 30% of the annual equity awards to each of the above-named executive officers and vest in three equal, annual installments with a first vest date of February 2, 2022, subject in each case to the named executive officer’s continued service through each vesting date.

We maintain a tax-qualified 401(k) retirement plan for all employees who satisfy certain eligibility requirements under the plan. The plan provides eligible employees with an opportunity to save for retirement on a tax-advantaged basis. Participants of our 401(k) plan are able to defer a percentage of their eligible compensation, subject to applicable annual Internal Revenue Code and plan limits. All participants’ interests in their deferrals are 100% vested when contributed. We also provide matching contributions under our 401(k) plan that generally vest over a 4-year period based on the participant’s employment. In February 2021, the Company reinstated its previously suspended match of 50% of the first 6% of eligible compensation contributed, for up to $2,500 per year. Pre-tax contributions are allocated to the participant’s individual account and are then invested in selected investment alternatives according to the participant’s directions. The 401(k) plan is intended to qualify under Internal Revenue Code Section 401(a) with the plan’s related trust intended to be tax exempt under Internal Revenue Code Section 501(a). As a tax-qualified retirement plan, the 401(k) plan allows contributions, and earnings on those contributions, not to be taxable to the employees until distributed from the 401(k) plan.

We generally do not provide perquisites or other personal benefits to our named executive officers.

Pursuant to our Insider Trading Policy, all employees (including executives) are prohibited from engaging in transactions in publicly traded options and other derivative securities with respect to our common stock, including any hedging or similar transaction designed to decrease the risks associated with holding company securities. Our named executive officers are also prohibited from pledging company securities as collateral or holding company securities in a margin account.

Our compensation committee is required to assess whether our compensation policies and practices and, in particular, our performance-based compensation practices, encourage executives or other employees to take unnecessary or unreasonable risks that could threaten the long-term value of the Company or that are reasonably likely to have a material adverse effect on the Company. Our compensation committee does not believe that our compensation policies and practices create risks that are reasonably likely to have a material adverse effect on the Company. Management believes that our practices adequately manage this risk because:

Our compensation committee is responsible for the executive compensation programs for our executive officers. In order to decide how to compensate our executive officers, our compensation committee considers the recommendations of our Chief Executive Officer regarding compensation for the respective executive officers that report to him based on our results and each executive officer’s contribution toward these results and overall performance. Our Chief Executive Officer does not make recommendations as to his own compensation.

Our compensation committee also decides how to compensate our executive officers, including the Chief Executive Officer, by considering competitive market data. While our compensation committee is authorized to retain the services of executive compensation advisors to establish compensation programs and related policies, it did not retain an advisor during 2021. During 2021, we used information from Radford-AON to help us determine the appropriate level of overall compensation for our executive officers

In determining executive compensation, the compensation committee also considers, among other factors, the possible tax consequences to us and to our executives. To maintain maximum flexibility in designing compensation programs, the compensation committee, while considering company tax deductibility as one of its factors in determining compensation, will not limit compensation to those levels or types of compensation that are intended to be deductible.

The discussion of performance targets in this Compensation Discussion and Analysis section is exclusively in the context of executive compensation, and you should not use these targets for any other purpose or regard them as an indication of management’s expectations of future results.

The compensation committee has reviewed and discussed with management the section titled “Compensation Discussion and Analysis” above. Based on such review and discussion, the compensation committee recommended to the board of directors that the Compensation Discussion and Analysis be included in this proxy statement.

Respectfully submitted by the members of the compensation committee of the board of directors:

The following table provides information regarding the compensation paid to, or earned by, our named executive officers (each, an “NEO” and together, the “NEOs”) for each of our fiscal years ended December 31, 2021, 2020 and 2019.

The following table shows information regarding cash incentive and equity awards granted to our NEOs during our fiscal year ended December 31, 2021.

The following table sets forth information regarding outstanding stock options and stock awards held by our NEOs as of December 31, 2021. The closing price per share on the NYSE of our common stock as of December 31, 2021was $16.58 per share, which was used as the value of our common stock in the calculations.

The following table sets forth the number of shares of common stock acquired during 2021 by our NEOs upon the exercise of stock options and the vesting of stock awards and the value realized upon such exercise or vesting.

We do not provide a pension plan for our employees, and none of our NEOs participated in a nonqualified deferred compensation plan during 2021.

We entered into employment offer letters with certain of our NEOs in connection with commencement of employment with us. Mr. Trivedi, Mr. Bruening and Mr. Cochran are eligible to receive certain severance payments and/or benefits in connection with their termination of employment under various circumstances, including following a change in control, pursuant to written change in control and severance arrangements described below.

We entered into a Change in Control and Severance Agreement (each, an “Agreement” and together, the “Agreements”) with each of Mr. Trivedi, Mr. Bruening and Mr. Cochran.

Each Agreement provides that upon completion of at least one year of employment in an executive role, except in the case of Mr. Trivedi who did not have a one year threshold, if (a) we terminate the executive’s employment with us for any reason other than for cause and not due to the executive’s death or disability, or (b) the executive resigns for Good Reason (as defined in the Agreement), and in each case the termination does not occur during the Change in Control Period (as defined in the Agreement), the executive will receive the following severance benefits: (i) continuing payments of salary at a rate equal to executive’s base salary rate in effect immediately prior to the executive’s termination for a period of 12 months in the case of Mr. Trivedi or 9 months in the case of the other NEOs, and (ii) continuing payments to reimburse the executive for COBRA continuation coverage for a period of up to 12 months in the case of Mr. Trivedi or 9 months in the case of the other NEOs.

Each agreement further provides that if we terminate the executive’s employment with us for any reason other than cause and not due to the executive’s death or disability, or the executive resigns for Good Reason, and in each case the termination occurs during the Change in Control Period, the executive will receive the following severance benefits: (i) a lump sum cash payment equal to 100% of the greater of the executive’s salary in effect as of immediately prior to his employment termination or the Change in Control, (ii) a lump sum cash payment equal to 100% of the greater of the executive’s target bonus in effect for the year in which the executive’s employment terminates or the Change in Control occurs, (iii) continuing payments to reimburse the executive for COBRA continuation coverage for a period of up to 12 months, and (iv) 100% accelerated vesting of the executive’s outstanding equity awards, with any applicable performance goals considered achieved at the target levels (with certain exceptions as listed below).

The RSU equity awards granted to Mr. Cochran in 2020 specifically do not have any accelerated vesting.

In order to receive the severance benefits under the Agreement, the executive must sign and not revoke a release of claims in our favor and comply with confidentiality obligations.

As defined in the Agreements, “Cause” generally means the executive’s (i) repeated failure to perform his duties and responsibilities to the Company or abide in all material respects with the Company’s policies after receiving written notice, (ii) engagement in illegal conduct injurious to the Company in any material respect, (iii) material violation or material breach of his confidential information and invention agreement with the Company that is not cured within 20 days of written notice or is incapable of cure, or (iv) conviction or plea of no contest to a felony (other than motor vehicle offenses that do not materially impair the executive’s performance of his employment duties) or any crime involving fraud, embezzlement or other offense involving moral turpitude, and/or committing any act of embezzlement, dishonesty or fraud against or the misappropriation of material property belonging to the Company.

As defined in the Agreements, “Change in Control Period” generally means, subject to the occurrence of a Change in Control, the period beginning on the date that an agreement to enter into such Change in Control is signed and executed and ending on the date 12 months following such Change in Control. As defined in the Agreements, “Change in Control” generally means the occurrence of any of the following events: (i) a change in our ownership that occurs on the date that any one person or persons acting as a group (“Person”), acquires ownership of our stock that, together with the stock already held by such Person, constitutes more than 50% of the total voting power of our stock; or (ii) a change in our effective control that occurs on the date that a majority of members of our board of directors is replaced during any 12-month period by directors whose appointment or election is not endorsed by a majority of the members of our board of directors prior to the date of the appointment or election; or (iii) a change in the ownership of a substantial portion of our assets that occurs on the date that any Person acquires (or has acquired during a 12-month period) assets from us with a total gross fair market value equal to or more than 50% of the total gross fair market value of all of our assets immediately prior to such acquisition(s), excluding any transfer to an entity that is controlled by our stockholders immediately after the transfer and any transfer of assets by us to an entity, 50% or more of the total value or voting power of which is owned, directly or indirectly, by us. For purposes of this definition, gross fair market value means the value of our assets, or the value of our assets being disposed of, determined without regard to any liabilities associated with such assets.

As defined in the Agreements, “Good Reason” generally means the executive’s voluntary termination of employment with us within 90 days following the expiration of our cure period following one or more of the following occurring without the executive’s prior consent: (i) a material reduction in the executive’s gross base salary other than in connection with a similar reduction for all similarly situated employees; (ii) a material reduction in the executive’s authority, duties, or responsibilities; or (iii) a relocation of the executive’s principal place of work to a location that is more than 50 miles from his current principal work site for us. The executive may not resign for Good Reason without first providing us with notice within 60 days of the initial existence of the condition that he believes constitutes Good Reason identifying the grounds for Good Reason and a reasonable cure period of at least 30 days following the date of such notice, during which such grounds must not have been cured.

Each of Mr. Becker’s 2021 RSU and PSU agreements provides that if we terminate the Mr. Becker’s employment with us for any reason other than cause and not due to the executive’s death or disability, or the executive resigns for Good Reason, and in each case the termination occurs during the Change in Control Period, Mr. Becker will receive 100% accelerated vesting of the outstanding equity awards for the RSU and PSU grants made to him on February 2, 2021.

The following table provides an estimate of the payments and benefits that would be provided in the circumstances described above for each of the NEOs, assuming the triggering event took place on December 31, 2021 (the last business day of 2021) and based on the $16.58 closing price per share of our common stock on the NYSE on that date. A number of factors may affect the nature and amount of any potential payments or benefits, and as a result, the payments and benefits actually paid (if any) may be different. For example, a triggering event may occur on a date other than December 31, 2021, the price per share of our common stock on the date of the triggering event may be higher or lower than $16.58 or the assumptions relied upon in the estimate of potential payments and benefits below may not reflect the actual circumstances of the triggering event. Accordingly, there is no guarantee that a triggering event would produce the same or similar results as those estimated below.

The compensation committee retains discretion to provide additional benefits to executive officers upon termination or resignation if it determines the circumstances so warrant.

The following table summarizes our equity compensation plan information as of December 31, 2021. Information is included for equity compensation plans approved by our stockholders and equity compensation plans not approved by our stockholders. We will not grant equity awards in the future under any of the equity compensation plans not approved by our stockholders included in the table below.

Presented below is the ratio of annual total compensation of our Chief Executive Officer to the annual total compensation of our median employee. The ratio is a reasonable estimate calculated in a manner consistent with Item 402(u) of Regulation S-K under the Exchange Act. SEC rules for identifying the median employee allow companies to apply various methodologies and assumptions and, as a result, the pay ratio reported by us may not be comparable to the pay ratio reported by other companies.

As determined in accordance with SEC rules, the fiscal year 2021 annual total compensation was $3,135,250 for our Chief Executive Officer, as reported in the “Summary Compensation Table” above. We estimate that the fiscal year 2021 annual total compensation for the median of all employees, excluding our Chief Executive Officer, was $178,144. The resulting ratio of our Chief Executive Officer’s annual total compensation to that of the median of all employees, excluding our Chief Executive Officer, for fiscal year 2021 is 17.6 to 1.

As permitted by SEC rules, to identify our median employee, we elected to use the annual total cash compensation of each employee for fiscal year 2021. For these purposes, annual total cash compensation included annual base salary or hourly wages, cash incentives, commissions, comparable cash elements of compensation in non-U.S. jurisdictions and grant date fair market value of equity compensation granted in fiscal year 2021. We utilized internal human resources records with all foreign currencies converted to U.S. dollars. All amounts were annualized for permanent employees who did not work for the entire year. We identified the employee with the median compensation calculated as described above. We calculated annual total compensation for the median employee using the same methodology used to calculate the “Total” column of the “Summary Compensation Table.” We selected the median employee from among our global population of employees as of the end of fiscal year 2021. We did not exclude any employees whether pursuant to the de minimis exemption for foreign employees or any other permitted exclusion.

The following table sets forth certain information with respect to the beneficial ownership of our common stock as of April 29, 2022 for:

We have determined beneficial ownership in accordance with the rules of the SEC, and thus it represents sole or shared voting or investment power with respect to our securities. Unless otherwise indicated below, to our knowledge, the persons and entities named in the table have sole voting and sole investment power with respect to all shares that they beneficially owned, subject to community property laws where applicable.

We have based our calculation of the percentage of beneficial ownership on 75,824,501shares of our common stock outstanding as of April 29, 2022. We have deemed shares of our common stock subject to stock options that are currently exercisable or exercisable within 60 days of April 29, 2022 or issuable pursuant to RSUs which are subject to vesting conditions expected to occur within 60 days of April 29, 2022 to be outstanding and to be beneficially owned by the person holding the stock option or RSU for the purpose of computing the percentage ownership of that person. We did not deem these shares outstanding, however, for the purpose of computing the percentage ownership of any other person.

Unless otherwise indicated, the address of each beneficial owner listed in the table below is c/o A10 Networks, Inc., 2300 Orchard Parkway, San Jose, California 95131. The information provided in the table is based on our records, information filed with the SEC and information provided to us, except where otherwise noted.

We describe below all transactions and series of similar transactions, since the beginning of our last fiscal year, to which we were a party or will be a party, in which:

We are party to an investors rights agreement which provides, among other things, that certain holders of our common stock have the right to demand that we file a registration statement, or request that the shares of such stock be covered by a registration statement that we are otherwise filing, subject to certain exceptions. Robert Cochran, our Executive Vice President, Legal and Corporate Collaborations, and certain entities affiliated with Summit Partners, L.P., which hold more than 5% of our outstanding capital stock and one of whose managing directors, Peter Y. Chung, is a member of our board of directors, are parties to the investors rights agreement.

We have entered into employment arrangements with certain of our current and former executive officers. See “Executive Officer Employment Agreements.”

We have also entered into indemnification agreements with certain of our officers and directors that require us to indemnify our officers and directors to the fullest extent permitted by Delaware law.

The audit committee of our board of directors has the primary responsibility for reviewing and approving transactions with related parties. The audit committee charter provides that the audit committee may review and approve in advance any related party transactions.

We have adopted a formal written policy providing that our executive officers, directors, nominees for election as directors, beneficial owners of more than 5% of any class of our common stock, any member of the immediate family of any of the foregoing persons, and any firm, corporation, or other entity in which any of the foregoing persons is employed, is a general partner or principal or in a similar position, or in which such person has a 5% or greater beneficial ownership interest, is not permitted to enter into a related party transaction with us without the consent of the audit committee, subject to the exceptions described below. In approving or rejecting any such proposal, the audit committee is to consider the relevant facts and circumstances available and deemed relevant to the audit committee, including, whether the transaction is on terms no less favorable than terms generally available to an unaffiliated third party under the same or similar circumstances, and the extent of the related party’s interest in the transaction. The audit committee has determined that certain transactions shall be deemed to be pre-approved by the audit committee, even if the aggregate amount involved will exceed $120,000, including certain employment arrangements of executive officers, director compensation, transactions with another company at which a related party’s only relationship is as a non-executive employee or beneficial owner of less than 5% of that company’s shares, transactions where a related party’s interest arises solely from the ownership of our common stock and all holders of our common stock received the same benefit on a pro rata basis, and transactions available to all employees generally.

Section 16(a) of the Exchange Act requires that our executive officers and directors, and persons who own more than 10% of our common stock, file reports of ownership and changes of ownership with the SEC. Based on our review of forms we received, or written representations from reporting persons that all reportable transactions were reported, the Company believes that during our fiscal ended December 31, 2021, all Section 16(a) filing requirements were satisfied on a timely basis, except that Mr. Becker filed one report late with respect to a sales transaction and each of Mr. Becker, Mr. Bruening, Mr. Cochran and Mr. Trivedi made a late filing with respect to a performance-based award converting into a time-based award upon achievement of a milestone, in each case due to administrative error and corrected as soon as the error was detected.

Our financial statements for our fiscal year ended December 31, 2021 are included in our Annual Report on Form 10-K. This proxy statement and our annual report are posted on our website at http://investors.a10networks.com and are available from the SEC at its website at www.sec.gov. You may also obtain a copy of our annual report without charge by sending a written request to A10 Networks, Inc., Attention: Investor Relations, 2300 Orchard Parkway, San Jose, California 95131.

The board of directors does not know of any other matters to be presented at the Annual Meeting. If any additional matters are properly presented at the Annual Meeting, the persons named in the proxy card will have discretion to vote the shares of our common stock they represent in accordance with their own judgment on such matters.

It is important that your shares of our common stock be represented at the Annual Meeting, regardless of the number of shares that you hold. You are, therefore, urged to vote by telephone or by using the Internet as instructed on the proxy card or execute and return, at your earliest convenience, the proxy card in the envelope that will be provided with the proxy card.