As a Platform Engineer at Refractal, you will own the core platform, building the APIs, SDKs, and data layers that secure autonomous systems. Working directly with founders from MIT and NASA, you will design multi-tenant isolation, real-time observability tools, and a security context graph to help global organizations defend against adaptive AI threats.
Platform Engineer at Refractal
Join Refractal to build the security infrastructure for the autonomous future. As a Platform Engineer, you'll own the APIs and data layers for the Security Context Graph—a platform used by governments and high-assurance AI startups to defend against adaptive cyber threats. Founded by veterans of NASA, MIT, and Microsoft, and recognized by Google's Gemini Cybersecurity Forum, Refractal offers the chance to work on high-stakes, real-world AI deployments. This London-based role provides meaningful founding equity and a direct hand in shaping the technical direction of a leading European AI security company.
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Location
London, United Kingdom
Compensation
Not Disclosed + Equity
Company
Refractal
Role overview
Refractal is building the security infrastructure for autonomous systems. Our founding team combines technical pedigree from MIT, NASA, and the U.S. military with commercial experience in VC and startups. We are starting with monitoring for employee AI usage. Unlike competitors, we are concentrating on native multimodality across browsers, file systems, and beyond.
Refractal is backed by leading institutional investors including Creator Fund, Eka, and Blue Wire Capital. We have also received compute support from Google Cloud, Microsoft for Startups, as well as being recognised by MIT’s flagship CSAIL AI lab as part of CSAIL Alliances.
What you will do
- Design and build robust FastAPI services and versioned SDKs that serve as the primary interface for security teams and AI agents.
- Architect identity and access control systems, ensuring strict multi-tenant isolation and secure authentication across all data and event layers.
- Develop real-time operator dashboards and observability tools using React to trace agent actions, attacker trajectories, and enforcement decisions.
Who this is a fit for
- Proven expertise in backend engineering with Python and FastAPI, focusing on high-consequence APIs, relational databases, and multi-tenant security models.
- Hands-on experience with observability systems and event streams to trace complex actions across distributed services or AI deployments.
- Full-stack capability with React and JavaScript to build data-dense security consoles and operator tools that integrate seamlessly with core APIs.
Why this role is remarkable
- Join an elite founding team with pedigree from NASA, Microsoft, and MIT, building the “Security Context Graph” for high-assurance AI deployments.
- Refractal is the only British AI security company in Google’s Gemini Cybersecurity Startup Forum and is already securing European government AI systems.
- Take end-to-end ownership of critical infrastructure, transitioning from founding-stage engineering to a senior technical leadership role as the company scales.
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