Horizon3 AI

Horizon3.ai is a cybersecurity company founded in 2019 that helps organisations find, fix and verify exploitable attack vectors before attackers can reach them. Its approach rests on autonomous penetration testing: rather than relying on periodic manual assessments or tools that generate unverified alerts, the company tests production systems continuously and reports on what is actually exploitable.

The firm's main product, NodeZero, is an autonomous penetration testing platform that assesses security posture across internal, external, cloud and hybrid environments, delivering production-safe tests and continuous validation. Its customer base ranges from small educational institutions to Global 100 enterprises and government agencies, and it operates in the education, public sector, enterprise and managed security services (MSSP/MSP) segments. In 2025 the company ranked 3rd among the fastest-growing firms in North America on the Deloitte Fast 500.

The work is motivated by a set of well-defined problems in security operations: ineffective tools, false positives, alert fatigue and a shortage of skilled practitioners. The team combines former U.S. Special Operations cyber operators, startup engineers and cybersecurity practitioners, giving it a practitioner-oriented culture that blends special operations cyber experience with startup engineering. The company is headquartered in North America.