Founding RL Engineer / Researcher (Remote, London/Paris)

About the role

We are building a pioneering AI startup focused on real‑human behavioural data to create long‑horizon reinforcement‑learning environments. As a founding RL Engineer/Researcher you will shape the core technology stack, design complex training environments, and help launch the product with frontier AI labs as early customers.

Key responsibilities

• Design, implement and iterate on 10‑100+ step RL environments that mirror real‑world decision workflows.
• Develop training pipelines, data collection, and evaluation frameworks tightly integrated with the environments.
• Collaborate with domain experts to capture human reasoning and decision‑making data.
• Scale the infrastructure to support large‑scale training signals and model evaluation.
• Contribute to the founding team’s technical vision and roadmap.

Required profile

• Passion for reinforcement learning and long‑horizon problem solving.
• Ability to work fast, think from first principles and thrive without a predefined playbook.
• Comfort with ambiguity and a startup mindset.
• Willingness to join a founding team and take ownership of critical components.

Required skills

• Reinforcement Learning
• RL environment design

What we offer

• £300,000 base salary plus founding equity at a ~$30M pre‑seed valuation.
• Immediate access to frontier AI labs as paying clients.
• Hybrid work arrangement with remote flexibility, based in London or Paris.
• Opportunity to shape a cutting‑edge product from day one.