Sthenos AI

Founded in 2025, Sthenos AI is a defense software developer based in Athens, Greece working in c4isr, defense software & ai.

Sthenos AI is the artificial intelligence division of EFA Group, a Greek defence and security group. Established as a spin-off of EFA Group in 2025, the company develops secure AI systems for command and control (C2) and next-generation command, control, communications, computers, cyber, intelligence, surveillance and reconnaissance (C6ISR). Its flagship Sthenos AI Platform combines machine learning, computer vision and decision support in a unified, on-premise architecture designed for edge, tactical and command environments. The company works in collaboration with Scytalys and emphasises meaningful human oversight, reliability, auditability and certifiable AI in defence applications. It operates with technology partners including Hewlett Packard Enterprise, Infinitum, Red Hat and NVIDIA for its AI infrastructure.