Horizon3 has promoted Ellen Sundra to Chief Customer Officer, expanding her responsibilities across six customer-facing functions as the cybersecurity company continues to scale its NodeZero Proactive Security Platform.
Sundra, formerly Vice President, Customers, will now oversee Sales Engineering, Customer Success, Support, Enablement, Renewals, and Field CTOs. Her expanded role focuses on helping customers achieve measurable security outcomes, increase adoption of NodeZero, and realize value from the platform faster.
The promotion puts Horizon3’s pre-sales and post-sales customer functions under unified leadership. The company said the move is intended to create greater continuity from the initial evaluation of NodeZero through implementation, training, ongoing technical support, renewals, and broader platform adoption.
Horizon3 now serves more than 7,000 organizations globally, including defense agencies, Fortune 10 companies, multinational banks, and healthcare providers. The company said Sundra has played an important role in building the teams and processes needed to support that expanding customer base while driving strong retention and revenue growth.
NodeZero autonomously identifies exploitable security exposures, shows what attackers could achieve, and verifies whether remediation efforts have closed identified attack paths. Sundra’s organization will help customers use those findings to establish repeatable testing, remediation, and verification processes as their security requirements evolve.
Sundra joined Horizon3 in December 2024 and brings decades of technical and customer leadership experience. Before joining the company, she spent nearly 15 years at Forescout, progressing from Federal Systems Engineer through global systems engineering leadership before becoming Chief Customer Officer.
Horizon3 positions NodeZero as an AI-native proactive security platform that enables organizations to continuously test defenses and prioritize exploitable risks. The company was recently named the Fastest Growing Cybersecurity Company in North America by the Deloitte Technology Fast 500 and was recognized by Fast Company as one of its Most Innovative Companies of 2026.
KEY QUOTES:
“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. 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.”
Snehal Antani, CEO And Co-Founder Of Horizon3
“Every team I lead shares responsibility for the customer’s success. 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.”
Ellen Sundra, Chief Customer Officer Of Horizon3
