Wen Jiayi

Jiayi Weng is a research engineer at OpenAI, where he serves as the post-training infrastructure lead and works on scaling reinforcement learning from human feedback pipelines. He is credited as a contributor to ChatGPT and subsequent models including GPT-4, GPT-4 Turbo, GPT-4o, and GPT-5. He is best known as the creator of Tianshou, a widely used PyTorch deep reinforcement learning library, and EnvPool, a highly parallel reinforcement learning environment execution engine. He holds degrees from Tsinghua University and Carnegie Mellon University.