eSentire Appoints Cybersecurity Industry Veteran James C. Foster as CEO
Cyber Security / Threat Detection | 4 min read
eSentire, The Authority in AI-powered Managed Detection and Response (MDR), has announced the appointment of James C. Foster as Chief Executive Officer. Foster assumes the role from Kerry Bailey, who is retiring after leading the company through a period of sustained growth. A globally recognised cybersecurity entrepreneur and executive, Foster brings more than 25 years of expertise in artificial intelligence, cybersecurity, and company building to the role.
A Career Defined by Category-Creating Security Companies
Foster is best known as the founder and former Chairman and CEO of ZeroFox, where he built and successfully took public the industry's leading external cybersecurity platform. During his tenure, ZeroFox achieved more than 30 consecutive quarters of ARR growth, expanded across four continents, completed five strategic acquisitions, and grew into a multi-hundred-million-dollar global enterprise protecting thousands of organisations worldwide.
Earlier in his career, Foster founded Ciphent, which quickly became one of the fastest-growing cybersecurity companies in the United States — serving more than 1,000 enterprise customers including 43 of the Fortune 100 before merging with Accuvant (now Optiv). He subsequently helped scale Accuvant toward $500 million in annual revenue. His career also spans foundational roles at Guardent (acquired by VeriSign), Foundstone (acquired by McAfee), IronCircle (acquired by QuickStart), and as an Operating Partner at NightDragon — a leading cybersecurity venture capital and growth firm — alongside service supporting US national security at the Department of Defense.
Foster holds advanced education from Capitol Technology University and The Wharton School, University of Pennsylvania. He is a widely published author of more than a dozen books on advanced threats, cyberattacks, and defence strategies, and a frequent speaker at industry forums on AI, cyber workforce development, and enterprise security strategy.
Foster's Vision for eSentire
"eSentire has built something truly exceptional — a 25-year track record of growth and protecting many of the world's most targeted organisations, a world-class team of threat hunters and security analysts, and an AI-powered platform in Atlas that is unmatched in the MDR space. The threat landscape is evolving faster than ever, and organisations need a cybersecurity partner who can meet that pace with both agentic and human expertise. I am honoured to work alongside this outstanding team and ensure that eSentire is delivering on our mission: hunting, investigating, and stopping cyber threats before they become business-disrupting events."
— James C. Foster, CEO, eSentire
Words from the Outgoing CEO and the Board
"Foster brings exceptional vision, deep industry expertise, and a proven track record of building world-class security organisations. eSentire has never been better positioned — with the team, the technology, and the mission to redefine what Managed Detection and Response means for organisations around the world."
— Kerry Bailey, Outgoing CEO, eSentire
"As the market rapidly evolves toward more proactive, AI-driven and intelligence-led security operations, we believe Foster is the ideal leader to guide eSentire into its next chapter. His experience building and scaling innovative cybersecurity platforms, combined with his deep understanding of modern adversaries, will help accelerate our vision of delivering continuous protection and measurable security outcomes for customers worldwide."
— John Becker, Chairman, eSentire
"His experience taking platforms from early growth to global scale, combined with his deep understanding of the evolving threat landscape, makes him exceptionally well suited to lead eSentire in its next phase. We believe Foster's leadership will accelerate the company's innovation, strengthen its position as a trusted partner for organisations worldwide, and drive long-term value for customers and shareholders alike."
— Lauren Zletz, Managing Director, Warburg Pincus and eSentire Board Member
About eSentire and the Atlas XDR Platform
Founded in 2001, eSentire protects the critical data and applications of more than 2,000 organisations across 80+ countries and 35 industries. The company's AI-powered Atlas XDR Cloud Platform combines multi-agent AI, 24/7 threat hunting, and proven security operations to deliver outcomes-driven protection at scale — hunting, investigating, and stopping cyber threats before they become business-disrupting events.
Key Takeaways
- • James C. Foster has been appointed CEO of eSentire, succeeding Kerry Bailey who is retiring after leading the company through a period of sustained growth.
- • Foster is the founder and former CEO of ZeroFox — the company achieved 30+ consecutive ARR growth quarters and became a multi-hundred-million-dollar global enterprise under his leadership.
- • His earlier work at Ciphent served 1,000+ enterprise customers including 43 Fortune 100 companies, before scaling Accuvant toward $500M in annual revenue.
- • eSentire's Atlas XDR Cloud Platform protects 2,000+ organisations across 80+ countries with multi-agent AI and 24/7 threat hunting.
- • Backed by Warburg Pincus, the appointment signals eSentire's commitment to proactive, AI-driven, intelligence-led security operations at scale.