AI-native proactive security company Horizon3 has announced the promotion of Ellen Sundra to Chief Customer Officer (CCO). Formerly serving as Vice President of Customers, Sundra will now oversee six core customer-facing operations to accelerate value realization and platform adoption for users of the NodeZero® Proactive Security Platform.
Horizon3 promoted Ellen Sundra to Chief Customer Officer, expanding her leadership remit to cover six key customer-facing departments.
Her expanded portfolio includes Sales Engineering, Customer Success, Support, Enablement, Renewals, and Field CTOs.
Sundra joined Horizon3 in December 2024 after spending nearly 15 years at Forescout Technologies, where she previously served as CCO.
The appointment supports Horizon3's scaling strategy as its customer base surpasses 7,000 organizations globally.
Horizon3 was recently named the Fastest Growing Cybersecurity Company in North America by the Deloitte Technology Fast 500.
As organizations increasingly turn to automated penetration testing and continuous threat exposure management (CTEM), bridging pre-sales guidance with long-term technical enablement is critical. Sundra’s expanded role unites these touchpoints, ensuring that security teams receive continuous technical support to translate NodeZero's automated attack paths into verified remediation fixes.
"Ellen epitomizes our core value of being customer obsessed. Her technical expertise and customer empathy has played a key role in helping Horizon3 cultivate radical champions that love our product and brand," said Snehal Antani, CEO and co-founder of Horizon3. "In addition, she's helped build out the team and processes necessary for us to scale pre-sales and post-sales support to the 7,000+ companies that rely on Horizon3 to improve their cyber resilience, resulting in best-in-class retention and revenue expansion metrics across the globe."
With decades of cybersecurity leadership experience—including global engineering and customer operations roles at Forescout—Sundra focuses on driving lasting partnerships and measurable risk reduction.
"Every team I lead shares responsibility for the customer’s success," said Sundra. "Customers should be able to count on us to understand their priorities, give them clear technical guidance and follow through as their needs change. My focus is on helping their teams become confident, effective users of NodeZero, with the knowledge and support to turn findings into verified fixes. That is how we earn long-term partnerships and help customers keep reducing risk."
About Horizon3
Horizon3, the AI-Native Proactive Security Company behind NodeZero®, shifts the advantage from attackers to defenders by giving organizations the power to fight AI with AI. NodeZero, the World’s Best AI Hacker™, autonomously tests defenses at machine speed, safely uncovers and prioritizes exploitable attack paths, instantly verifies fixes, and drives a continuous hack, fix, verify loop. More than 7,000 organizations, including global defense agencies, Fortune 10 enterprises, multinational banks, and major healthcare providers, trust Horizon3 for security they can prove. Horizon3 was recently named the Fastest Growing Cybersecurity Company in North America by the Deloitte Technology Fast 500 and named one of the Most Innovative companies by Fast Company in 2026.
