• CEO & Co-Founder
    Brian O'Kelley

    As CEO of AppNexus, the world leader in real-time advertising technology, Brian and his team are building the company to be the lynchpin of the display advertising industry, offering a highly scalable ad technology platform upon which other companies build their advertising businesses. Widely considered a visionary in online advertising, Brian O’Kelley created the first successful ad exchange as CTO of Right Media (acquired by Yahoo! for $850MM in July 2007) before co-founding AppNexus. An innovator throughout his career, Brian was CEO of Netamorphosis, an early social networking and e-commerce site, co-founder of Cetova, a web-based reporting and analytics platform for enterprise financial systems, and EVP at LogicSpan, a consulting and technology integration firm specializing in real-time personalization and real-time ad optimization. Today, in addition to his role at AppNexus, Brian is also an active investor in and early-stage advisor to dozens of ad technology companies in the ecosystem including Invite Media (now owned by Google), MediaMath, Media6Degrees and Solve Media. Brian has a computer science degree from Princeton University.

  • 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, Discovery
    Andy Atherton

    As SVP of Discovery at AppNexus, Andy is driving the delivery of Twixt, an innovative new solution for programmatic direct. Andy is also managing the AppNexus office in San Francisco, where he is based. 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.

  • SVP, Product
    Pat McCarthy

    Pat McCarthy is the Senior Vice President of Product at AppNexus where his team focuses on the planning and management of the company’s key initiatives, customer segments, and product strategy. Pat joined AppNexus 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.

  • CTO & SVP, Engineering
    Geir Magnusson

    Geir Magnusson, Jr. is Chief Technology Officer and SVP, Engineering, AppNexus, responsible for technology strategy and product delivery, as well as driving the evolution of the company’s product architecture. Geir was previously Vice President of Engineering at AppNexus leading the development of real-time auction, decisioning and data systems as well as the company’s mobile technologies.Geir has served as a technical executive and leader for companies including Function(x) – now Viggle – Gilt Groupe, 10gen, Joost, Adeptra, Bloomberg, and Intel, and has built systems and solutions for industries ranging from financial markets to fraud contact to digital audio to mobile consumer. He also has broad experience in open source, having founded several significant open source projects, such as Apache Geronimo, Apache Harmony and Apache Velocity.Geir is a member of the Apache Software Foundation, and has represented the Foundation as a member of the Executive Committee of the Java Community Process, as well as served as a past member of the Board of Directors. He is also an international speaker on open source and software technology. Geir holds degrees in Physics and Electrical and Computer Engineering from Johns Hopkins University.

  • SVP, Global Services
    Brandon Atkinson

    Brandon Atkinson is Senior Vice President of Global Services at AppNexus, which offers the digital advertising industry’s most powerful, open and customizable technology platform. He also serves as the Co-chair of the People and Culture Leadership Team. Previously, 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, 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, Programmatic Media Companies
    Lauren Nemeth

    Lauren Nemeth is Senior Vice President, Programmatic Media Companies at AppNexus. Lauren has spent the majority of her career focused on helping digital media companies more efficiently manage their digital advertising businesses in real-time and exchange environments. At AppNexus, Lauren manages the go to market activities for some of the world's largest digital media businesses while serving as a resource to clients on market differentiation and corporate positioning. She joined AppNexus from Google in early 2010 where she managed the buy-side sales organization for Google’s DoubleClick Ad Exchange. At DoubleClick, Lauren pioneered many of the initial RTB and ad network partnerships for the DoubleClick Ad Exchange. She continued to grow the sales organization and RTB footprint after Google’s acquisition of the company. Lauren has a BA from the University of California Los Angeles in European studies with a concentration in economics.

  • 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, Strategy & Operations
    Casey Birtwell

    As Senior Vice President of Strategy & Operations, Casey is responsible for overseeing strategic alignment at AppNexus by ensuring the business is focused on the key initiatives and their execution, as well as sales, contract and business operations. 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.