14 min read
Implementing GRPO from Scratch: DeepSeek-R1's Reinforcement Learning Engine
A hands-on walkthrough of Group Relative Policy Optimization — the algorithm behind DeepSeek-R1's reasoning. I build the full GRPO training loop in pure PyTorch on a distilled 1.5B model, from verifiable rewards to the clipped objective, and explain why it drops the critic network entirely.
Reinforcement LearningGRPOLLMsDeepSeekPyTorch