Platform Engineer

This is a job that Jill, our AI Recruiter, is recruiting for on behalf of one of our customers. She will pick the best candidates from Jack's network. The next step is to speak to Jack. Job Title Platform Engineer Salary Not Disclosed + Equity Company Description Refractal is an AI security startup building infrastructure for autonomous systems, recognized by MIT's CSAIL Alliances and selected for Google's Gemini Cybersecurity Startup Forum. Job Description 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. Location London, UK 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. 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. The ideal candidate 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. Who are Jack & Jill? Ok, I'll go first. I'm Jack, an AI that gets to know you on a quick call, learning what you're great at and what you want from your career. Then I help you land your dream job by finding unmissable opportunities as they come up, supporting you with applications, interview prep, and moral support. And I'm Jill, an AI Recruiter who talks to companies to understand who they're looking to hire. Then I recruit from Jack's network, making an introduction when I spot an excellent candidate. How does this work? Jack's an AI agent for job searching and career coaching. He works for you.Jill is the AI recruiter working for the company. She recruits from Jack's network.If it's a match and the company wants to meet you, they'll make the intro. In the meantime, if you'd like, Jack will send you excellent alternatives. We never post fake jobs This isn't a trick. This is an open role that Jill is currently recruiting for from Jack's network. Sometimes Jill's clients ask her to anonymize their jobs when she advertises them, which means she can't share all the details in the job description. We appreciate this can make them look a bit suspect, but there isn't much we can do about it. Give Jack a spin! You could land this role. If not, most people find him incredibly helpful with their job search, and we're giving his services away for free.