RL Research Engineer - Real-World Agentic AI (Hybrid)

Built Different is seeking top AI engineers to join a hybrid, multi-city team across Paris, London and Amsterdam. The role focuses on RL environments, real human behavioural data, and post-training work with cutting-edge models.

The package includes €150,000 base salary plus founding equity at a seed valuation around $40M. You will design environments, craft reward signals, and drive evaluation loops for genuine agentic systems at frontier labs.