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

Built Different; Paris; Hybrid; EUR 128,000 - 173,000; Full time

Benefits offered by this job

Founding equity

Hybrid work

Job summary

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.

Qualifications

• Hands-on experience with RL environments and foundation models.
• Experience designing evaluation loops and reward signals.
• Ability to work with real human behavioural data.

Responsibilities

• Develop RL environments using real human behavioural data.
• Own the post-training loop: data, rewards, training runs, evaluation.

Job description

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.