Senior Software Engineer

Description Join Onyx Security and help build the control plane for autonomous AI in a fast-moving, high-impact environment. Onyx is building the control layer that enables enterprises to safely adopt and scale AI agents across the organization, with the visibility, governance, and operational control needed to understand what agents exist, what they do, how they behave, and what risks they introduce.  About the role Onyx is looking for a Software Engineer to help build the core of our AI security platform and advance our AI Control Plane. In this role, you will work on systems that help enterprises understand, monitor, and control how AI agents operate across their organizations. You will be responsible for building high-impact capabilities across the platform, working closely with Product, Security, and other engineers to turn complex problems into simple, reliable solutions. This role requires strong ownership, technical judgment, and the ability to move quickly while maintaining high engineering standards in a fast-growing startup environment. What you will do Design, build, and own end-to-end features across the platform, from backend services to user-facing workflows. Collaborate closely with Product to turn complex What you will bring into simple, reliable solutions. Own technical decisions from design through production, balancing speed, quality, and long-term maintainability. Requirements What you will bring 5+ years of backend software engineering experience in production environments. Strong fundamentals in system design, APIs, scalability, performance, and reliability. Proven end-to-end ownership: design, development, testing, rollout, and monitoring. High bar for code quality, with a practical approach to testing and maintainability. Strong ownership, autonomy, and ability to move fast on ambiguous problems. Product sense and good judgment in balancing technical tradeoffs with business impact. Clear communication and strong cross-functional collaboration skills. Nice to Have Experience in cybersecurity or cloud security. Familiarity with AI / LLM systems and production use cases. Tech Lead experience. Hands-on experience with Docker, Kubernetes, and cloud infrastructure.