Horizon3 AI, founded in 2019, builds autonomous penetration testing technology; its NodeZero platform continuously finds, fixes and verifies exploitable attack vectors across cloud, hybrid and on-premises environments.
Horizon3 AI is a cybersecurity company founded in 2019 that builds autonomous penetration testing technology. Its platform, NodeZero, continuously assesses an organisation's security posture across internal, external, cloud and hybrid environments, running production-safe autonomous pentests to identify exploitable attack vectors and verify that fixes hold. The company's stated aim is to let organisations find, fix and verify weaknesses before attackers can use them.
NodeZero is the engine behind Horizon3 AI's ranking as the third fastest-growing company in North America on the 2025 Deloitte Fast 500. Its customers range from small educational institutions to Global 100 enterprises and government agencies, spanning sectors that include education, the public sector, IT operations and SecOps, managed security services and penetration testing consulting. The company's geographic presence is in North America.
The engineering culture draws on an unusual mix of backgrounds: former U.S. Special Operations cyber operators, startup engineers and cybersecurity practitioners work alongside one another. The mission driving the work is specific - addressing ineffective security tools, false positives, alert fatigue and the shortage of skilled cybersecurity professionals. Technical domains in scope include autonomous penetration testing, attack surface assessment, continuous security validation, cloud and hybrid environment security, and offensive security automation.
