Mr. Gesser is Co-Chair of the firm’s Data Strategy & Security Group and leads the firm’s Artificial Intelligence practice. His practice focuses on advising major companies on a wide range of artificial intelligence, cybersecurity, and privacy matters. Mr. Gesser currently serves as AI counsel for approximately 150 clients, including many of the world’s leading asset managers and broker-dealers, several major insurers, global consulting firms, and other market leaders. He regularly advises boards and senior executives on AI governance, oversight, and risk mitigation.
Under his leadership, Debevoise has become recognized as one of the market’s leading AI legal teams. Chambers USA ranks him Band 1 for Artificial Intelligence and notes that he and the firm are “unmatched in their knowledge of AI, both technically and as a matter of risk evaluation and governance.” Chambers also reported that “[the Group’s] approach is practical and actionable… There is no matter too complex or too sophisticated for this team.”
Mr. Gesser is the creator of the firm’s pioneering Suite of Tools for Assessing AI Risk (“STAAR”), a subscription-based framework that helps clients evaluate and manage the evolving legal and regulatory risks associated with the development and deployment of AI. STAAR brings together a comprehensive collection of practical tools—including a vetted use-case library, policy templates, and regulatory trackers—and has been profiled by Law.com (“Debevoise & Plimpton Is Building a New Model for Delivering AI Adoption Advice”) and Law360 (“Debevoise Builds Tool to Help In-House Attys Assess AI Risk”). In October 2025, STAAR was shortlisted for the Financial Times Innovative Lawyers North America Awards in the “Innovation in New Legal Products” category.
Beyond his client work, Mr. Gesser drives the firm’s AI thought leadership, including Debevoise’s Data Blog, which has more than 3,000 subscribers and features approximately 500 articles, including nearly 200 on AI. He has spoken at over 30 conferences and corporate annual meetings in the past year and regularly leads AI-focused CLEs, webcasts, and practical workshops that draw hundreds of industry leaders and regulators.
Mr. Gesser has been recognized across the legal industry for his leadership in AI and data law. In addition to his Band 1 Chambers ranking for Artificial Intelligence, he is recommended by Chambers Global (2025) and Chambers USA (2025) as a leading lawyer for privacy and data security, with clients noting that he “is a phenomenal lawyer who provides balanced, clear perspectives on even the most complex situations.” Sources have also said he provides “truly sophisticated legal guidance”, and he is “reasoned, rational and business-focused.” He is also recognized as a Leading Lawyer in The Legal 500 US (2025), where sources have described him as “an amazing counselor who is able to apply his expertise to provide practical advice.” In 2022, he was named an “AI Visionary” by Relativity, a leading software developer, in its first annual list featuring leaders in AI.
Earlier in his career, Mr. Gesser served from 2010 to 2013 as Counsel to the Chief of the Fraud Section in the Criminal Division at the U.S. Department of Justice. He received both the Attorney General’s Exceptional Service Award and the FBI Director’s Award for Excellence – Outstanding Criminal Investigation in 2013.
He received his B.S. from the University of Manitoba in 1991 (Chemistry/Math), his LL.B. from the University of Manitoba in 1994, his LL.M. from the University of Cambridge in 1995 and his LL.M. from New York University in 1998.