After less than a year at Meta, the prominent AI researcher Andrew Tulloch is leaving for Anthropic.
He’ll start next week, an Anthropic spokesperson told Business Insider, and work on the startup’s inference and performance team, where he’ll aim to optimize the training of Anthropic’s AI models and how they respond to users.
As AI’s talent wars steam on, Tulloch has become one of the most sought-after researchers. He had worked at Meta for 11 years prior to this latest stint, leaving for OpenAI in 2023. At OpenAI, he helped train its GPT-4o, GPT-4.5, and o3 models. He then cofounded Thinking Machines Lab in 2025.
Last year, while he was…
