• CEO & Co-Founder
    Brian O'Kelley

    Brian O'Kelley is CEO and co-founder of AppNexus, the world’s largest independent ad tech company and one of the most successful technology companies in the history of New York. Widely considered a visionary in Internet advertising and heralded as “the new king of ad tech” by Forbes, Brian started AppNexus in 2007 to create a technology platform that would transform the advertising ecosystem. Immediately prior to founding AppNexus, Brian revolutionized the ad tech industry by inventing the first online ad exchange while he was CTO of Right Media (later sold to Yahoo! for $850 million in 2007). Today, Brian holds numerous additional patents that help AppNexus’ technology power the most innovative trading solutions and marketplaces for Internet advertising, and further the company’s mission to create a better Internet. Brian is also an active investor in and early-stage advisor to dozens of tech companies, including Invite Media (acquired by Google in 2010), MediaMath, Dstillery and Solve Media. Brian has been honored by Crain’s 40 Under 40, Adweek 50, Silicon Alley 100, and was recognized as an E&Y Entrepreneur of the Year in the New York region in 2012. He holds a BSE in computer science from Princeton University where he is an active alumnus. Brian lives in New York City with his wife and daughter.

  • President
    Michael Rubenstein

    Michael has served as President of AppNexus since joining the company in September 2009. He oversees the company's global commercial functions, including Sales, Client Services and Marketing. Prior to joining AppNexus, Michael founded and served as VP and General Manager of Google's DoubleClick Ad Exchange. During his tenure at Google/DoubleClick, he held executive positions including VP of Strategic Accounts, where he spearheaded the company's landmark ad technology partnership with AOL. Michael joined DoubleClick in 2001 as part of the company's acquisition of FloNetwork, an email marketing ASP. Michael holds a BA from McGill University and an MBA from Columbia Business School.

  • Chief Financial Officer & Chief Operating Officer
    Jonathan Hsu

    Jonathan is Chief Financial Officer and Chief Operating Officer of AppNexus. A respected media and tech industry veteran, he previously served as CEO of Recyclebank, one of Fast Company’s “50 Most Innovative Companies in the World.” Prior to that, Jonathan spent 11 years in a number of executive roles – including CEO, COO, and CFO – at 24/7 Media, leading the company through its $649 million sale to WPP, the world leader in marketing communications. Jonathan was also an M&A investment banker at JP Morgan. Jonathan is a Director on Evidon’s Board, an advisor to Tribeca Venture Partners, and a mentor in the NYC Venture Fellows Program. He has served on the World Economic Forum Technology Pioneers Council, Media.NYC.2020 Committee, Green.NYC.2025 Committee, and White House Forum on Business Innovation. Jonathan holds a BA in Economics from Harvard University and an MBA in Strategic Management and Finance from the Wharton School at the University of Pennsylvania.

  • Chief Information Officer
    Igor Shindel

    As CIO of AppNexus, Igor Shindel focuses on technology strategy, product delivery, and building one of the best tech teams in the world. Prior to AppNexus Igor consulted for 12 years on technology strategy and worked with a diverse set of clients including the Metropolitan Museum of Art and PC Connection, Zagat and Google, eBay and Brooks Brothers, Art Technology Group and Sesame Workshop. Before starting his consulting practice, Igor worked as engineer, consultant, manager, VP, GM, locksmith, and actuarial for companies including Time Inc., WNET/Channel 13, and A&E Television.

  • SVP & GM, Marketplaces
    Andy Atherton

    As SVP and General Manager of Marketplaces, Andy oversees the portfolio of products that connect buyers and sellers on the AppNexus platform. Previously, Andy drove the development and launch of Twixt, an innovative new solution for programmatic direct. A well-known and respected executive in digital advertising, Andy previously spent four years as COO and cofounder of Brand.net, a pioneer in programmatic reserve technology and a leading digital media buying solution for top brands. Prior to Brand.net, he was Vice President of Pricing & Yield Management for Yahoo!, responsible for maximizing monetization of a global portfolio of display inventory worth $2B annually. Before Yahoo!, Andy was president and cofounder of Optivo, a venture-backed startup that developed price optimization software for ecommerce retailers. Andy received a BS in Mechanical Engineering from M.I.T.

  • Chief People Officer
    Brandon Atkinson

    Brandon Atkinson is the Chief People Officer of AppNexus. In this role, Brandon is responsible for providing leadership and direction for all initiatives and programs involving AppNexians, including but not limited to human resources, talent acquisition, talent development, benefits, and compensation. Brandon previously served as a the SVP of Services, growing Global Services to a 170-person, world-class organization. Before joining AppNexus, Brandon worked at start-up Opsware as Director of Global Services Operations & Education Services. After two years, he was appointed Site Executive, Romania, where he started Opsware's first off-shore engineering office and built it to 40 people over a 12-month period. After Opsware's acquisition by HP for $1.6B in 2007, Brandon became Solution Director, EMEA, Business Service Automation. Prior to that, Brandon was Atlantic Director of Peter Marin Associates, which was acquired by ACS (Affiliated Computer Services), where he ran Sales and Services teams. Early in his career, Brandon worked for the City of New York, Office of Technology, before joining his first start-up, CitySoft, where he was Managing Director, NY. He has also served with AmeriCorps*VISTA as a community organizer for a nonprofit housing provider in Anchorage Alaska. Brandon has a Bachelor's degree in History from Livingston College at Rutgers University and earned highest honors for his thesis work. He also has a Master's degree in Public Affairs from the LBJ School of Public Affairs at the University of Texas-Austin.

  • SVP & GM, Programmatic Media Companies
    Casey Birtwell

    Casey Birtwell is the Senior Vice President and General Manager of AppNexus' Programmatic Media Companies (PMC) business, where he oversees the product, sales, engineering, services, and marketing teams responsible for products serving AppNexus' PMC clients. Casey joined the company as SVP, Strategy & Operations, where he was responsible for overseeing strategic alignment and execution at AppNexus. Casey joined AppNexus in 2014 after holding key leadership roles at Avaya, a private $5 billion global provider of business communications applications, systems and services. In 2008, Casey was recruited to lead the execution of Avaya Global Services’s strategic transformation which resulted in a 15+ point margin improvement and then rounded out his extensive services experience in 2010 by leading the product business for Avaya Government Solutions, a $350 million wholly owned subsidiary of Avaya. Prior to Avaya, Casey was a Managing Director with BearingPoint, Inc. (formerly KPMG LLP) where, in addition to his practice responsibilities, Casey was ultimately responsible for the firm’s global relationship with JP Morgan Chase and was named COO of BearingPoint’s North American Financial Services business unit. Before joining BearingPoint, Casey was General Manager of The Firm Advantage, Inc., and a Consultant at Accenture, Ltd. (formerly Andersen Consulting). Casey graduated Magna Cum Laude from Babson College with a BS in Finance and studied at the London School of Economics.

  • SVP & GM, Publishers
    Ryan Christensen

    Ryan Christensen serves as the Senior Vice President and General Manager of AppNexus’ Publisher business. In this role, Ryan leads product development for the segment and manages commercial relationships with AppNexus’ major Publisher clients. Prior to joining AppNexus in 2013, Ryan served as General Manager of Ad Product at Zynga, where he was responsible for the company’s proprietary ad platform and provider integrations across mobile, video and desktop display ad products. Prior to Zynga, Ryan spent four years at Brand.net in senior product and BD leadership roles, working with top tier Publishers to develop innovative programmatic buying capabilities and yield management solutions.Before joining the world of digital advertising, Ryan was a founder and CEO of Sentrik, an enterprise security company; ran product management and marketing for Rocket Network; and managed engagements for RB Webber & Co, a Silicon Valley strategy consultancy and venture fund. Ryan received a BS in Mechanical Engineering from MIT.

  • General Counsel
    Nithya Das

    As AppNexus' General Counsel, Nithya oversees the Company's global corporate, commercial, intellectual property and regulatory legal affairs. Nithya joined AppNexus in 2011 and helped develop the Company's legal strategy during a period of high growth. Immediately prior to joining AppNexus, Nithya was a senior associate in the New York office of Goodwin Procter LLP where she represented public and private growth technology companies in a variety of industries. At Goodwin Procter, Nithya led numerous growth equity financings, mergers and acquisitions and public equity offerings. She also helped create the Founder's Workbench, a free, online resource that helps entrepreneurs navigate legal and operational challenges commonly faced by startups. In addition to her role at AppNexus, Nithya is an advisor to early stage starts-ups and a regular speaker and writer on topics relevant to technology companies. Nithya is also the writer behind an award winning recipe and photography blog. Nithya holds a Bachelors Degree in Business Administration from the SC Honors College at USC and a JD, cum laude, from Brooklyn Law School.

  • SVP, People
    Michelle Dvorkin

    As Senior Vice President, People, Michelle manages all aspects of human resources and people matters. She works closely with senior management, developing and implementing leadership plans and strategies in furtherance of overall business goals. Her main objective is to ensure that AppNexus has the best talent in the industry by managing a competitive compensation and benefits structure, focusing on company culture and helping to implement the company’s core values. Michelle is also co-chair of the People & Culture Leadership Team at AppNexus (PCLT).With more than 20 years of experience in the field, Michelle previously served as Senior Director, Human Resources at Lot18 and as Director of Human Resources at Ogilvy & Mather. She was also Director of Human Resources at Quigo Technologies and at AOL upon its acquisition of Quigo 2007. Michelle began her career at Primedia.In addition to her work at AppNexus, Michelle serves on the Board of Directors of the Pelham Jewish Center. She holds an MS in Industrial and Labor Relations with an emphasis in Human Resource Management from Cornell University and a BA in Industrial Organizational Psychology from San Francisco State University.

  • SVP, Finance
    Kris Heinrichs

    Kris Heinrichs is Senior Vice President of Finance, responsible for the planning and operations of Accounting, Finance and Treasury. Previously Kris served as CFO of Recyclebank, a behavioral change platform that engages members online and offline to live a more sustainable life, where he managed Finance, Legal, Human Resources and Real Estate as well as operational roles such as Customer Care and Analytics. Prior to that Kris spent 12 years at 24/7 Real Media in a variety of Finance & Administrative leadership roles culminating in CFO. 24/7 Real Media, a pioneer in internet advertising and one of the leading independent advertising networks was acquired by WPP and subsequently merged with Xaxis. Kris started his career at KPMG, specializing in financial audits of public and private companies in the internet and media industries. Kris is a CPA and holds a BS/BA in Accounting from the University of Richmond. Kris serves on the Board of One in Four, a non-profit organization dedicated to Sexual Assault Prevention, and also served in the United States Army.

  • VP, Strategic Projects
    Andrew Q. Kraft

    Andrew serves as Vice President, Strategic Projects, where he defines and leads the company's key strategic initiatives with major partners to bring new offerings and value to the market. Recent projects include acting as interim CFO, finalizing partnerships with two major strategic partners, and leading the relationship with one of our largest corporate clients. Previously, Andrew served as VP, Business Development, where he was responsible for identifying and fostering strategic partnerships within the online advertising ecosystem. Prior to joining AppNexus in 2012, Andrew served as Senior Vice President, AMP® Publisher Solutions, for Collective where he led business development for the company’s audience management and monetization platform. Previously, he served as Vice President Member Services and Revenue Development for the Interactive Advertising Bureau (IAB), where he gained unique insight into the business and sales functions of companies involved in the programmatic buying and selling of ads. Andrew also founded Executivity, a digital marketing and management consulting firm specializing in revenue development strategies. Andrew studied Physics and Theater at the Massachusetts Institute of Technology. He lives in New Jersey with his wife and four children.

  • SVP, Marketing
    Pat McCarthy

    Pat McCarthy is the Senior Vice President of Marketing at AppNexus. In this role, Pat oversees the User Experience (UX), Documentation, Product Marketing, and Corporate Marketing functions, which includes brand marketing, event marketing, corporate communications, and marketing operations. Previously, Pat served as Senior Vice President of Product where his team focused on the planning and management of the company’s key initiatives, customer segments, and product strategy. Pat joined AppNexus in 2012 via the acquisition of Fantuition, the startup he co-founded. Previously Pat was a Vice President at Yahoo! and an early executive at Right Media. Pat holds a Bachelor’s Degree in Computer Science from the University of Oregon.

  • SVP, Technical Operations
    Tim Smith

    Tim Smith is an accomplished systems and network expert with a unique mix of technical, operations, and executive experience. Tim joined AppNexus in 2010 as VP of Technical Operations, and was promoted to SVP in 2012. Tim is responsible for the production service delivery infrastructure at AppNexus, including data centers, networks (internal and external), servers, storage, data warehouse appliances/subsystems, and other such systems, while also managing Corporate IT. During his tenure at AppNexus, Smith has substantially and consistently reduced operating costs on a per unit basis, built a highly regarded team of 40+, and greatly improved system stability during a period where the company has grown phenomenally (e.g. from 20 employees to over 500, from 600 servers to close to 6000). Smith started his career working for the Navy and later the Army’s Ballistic Research Lab as a lab technician and then network systems specialist. He was subsequently recruited to the private sector by Sun Microsystems as a network systems and Internet specialist, and later worked on Internet systems technologies at various companies including the first commercial Internet Service Provider, UUNET Technologies, followed by a number of other startups including Wayport, a boutique ISP, as well as VoIP pioneer Vonage. Additionally, Tim has worked as a consultant in Technology Operations, Information Security, Information Technology Governance, Risk Management, and Compliance (IT GRC), and Venture Capital due diligence.