Founding Research Engineer, RL/Reasoning

As an RL Engineer at BioStack, you will build reinforcement learning environments and post-training systems for healthcare AI.

BioStack is building the data and environment layer for medical AI: sourcing high-value clinical data, turning it into model-ready workflows, and building tasks, rewards, verifiers, benchmarks, and agent environments where models can learn against meaningful and measurable outcomes.

You will work across the full RL loop – from environment and reward design to training, evaluation, and iteration. Projects may span clinical reasoning, longitudinal patient care, diagnostic decision-making, chronic disease management, and biomedical research.