Senior Software Engineering

Senior Software Engineer, AI Simulation & Agent Infrastructure
Most software engineers build products. This role is about building the simulated worlds that frontier AI models learn, reason, and fail inside.

You’ll join a research-driven team developing the infrastructure used to train, evaluate, and improve autonomous AI systems. Their work has already helped establish some of the industry's most recognised evaluation benchmarks, and they’re now building increasingly sophisticated simulation environments that push AI agents beyond simple benchmarks into realistic, complex workflows.

You’ll own these environments end-to-end, combining product engineering with systems thinking. One week you could be building React interfaces that agents interact with. The next, designing FastAPI services, verification systems, or infrastructure that uncovers failure modes long before models reach production.

This is an engineering role with genuine research impact. You’ll work closely with Applied Researchers to turn new environment ideas into production-quality software, creating the data and tooling that helps improve the capabilities, reliability, and safety of frontier AI.

What you’ll build

End-to-end RL environments using React, TypeScript, Next.js, Python, FastAPI, and Postgres.

Agent tooling including trajectory review, verifier debugging, reward validation, and evaluation workflows.

Reusable frameworks that make new simulated environments faster to build and easier to maintain.

Internal tooling that improves environment quality, catches edge cases, and exposes adversarial behaviour before deployment.

You’ll spend as much time thinking about correctness, robustness, and evaluation quality as writing code. The problems are highly ambiguous, ownership is high, and you’ll have significant influence over technical direction.

You’ll be a good fit if you have

Strong full-stack engineering experience with modern TypeScript and React.

Experience designing production APIs and backend services with Python, FastAPI, or similar technologies.

A good understanding of modern LLMs, agent loops, tool calling, and AI applications.

Experience building complex production systems from architecture through deployment.

Curiosity around AI coding tools and a genuine interest in extending them through automation or custom tooling.

You’ll join an exceptionally high‑calibre team with deep experience building frontier AI systems, backed by leading investors and already working alongside many of the world's most advanced AI organisations. Their mission is ambitious: building the simulation infrastructure that helps create
more capable and more reliable AI.

Compensation
Up to $300K Base + meaningful equity

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