Max Schwarzer, a key figure in OpenAI's reasoning model development, has announced his departure to join Anthropic. Schwarzer, who played a pivotal role in the creation and post-training of OpenAI's o1 and o3 models, and led the team responsible for delivering GPT-5 series models, will now focus on reinforcement learning research at Anthropic. His move marks a significant shift in the AI research landscape, as he brings his expertise to the growing team at Anthropic.