Python Developer (London Area)

Full Stack Engineer – AI Safety Tools

Join a mission-driven team building critical infrastructure for AI safety

We're a small, fast-moving team building tools that help AI labs and tech companies evaluate and monitor advanced AI systems. Our work turns cutting-edge research into production-grade software that keeps AI deployment safe, transparent, and accountable.

You’ll be joining as the first Full Stack Engineer on a brand-new product team, with the chance to shape the tech, team, and product direction from day one. If you enjoy building meaningful tools with real-world impact — and care about AI being aligned with human values — this is the place to do it.

️ Tech Stack

• Backend: Python, FastAPI, Flask, monorepo architecture
• Frontend: React, TypeScript
• Infrastructure: AWS, EC2, DynamoDB, Docker
• Tools: Custom eval libraries, observability tooling, real-time agent monitoring systems

What You’ll Work On

• Build full-stack features from architecture to production: REST APIs, frontends, and secure backend systems
• Translate complex AI safety evaluations into intuitive, scalable products for external users
• Help design and implement tools like:
• Evaluations API for enterprise-scale AI model testing
• Real-time agent monitoring for catching risky behavior in deployed LLM agents
• Work closely with our Head of Product and AI researchers — you’ll help turn internal research tools into robust customer-facing products
• Contribute to product decisions, help shape our engineering culture, and bring a user-centered mindset to technical work

✅ What We’re Looking For

• 6+ years as a Full Stack or Backend Engineer building production-grade software
• Strong backend experience with Python (FastAPI, Flask, or Django)
• Confident with modern frontend frameworks like React and TypeScript
• Skilled in building and maintaining APIs, cloud services (AWS or GCP), and containerized deployments
• Strong problem-solving skills, and comfortable in fast-moving, ambiguous environments
• Bonus: You've built a product from 0 to 1, led a tech stack decision, or worked in ML/AI environments