Thinking Machines Lab has officially confirmed that Andrew Tulloch, one of its co-founders, is leaving the company to join Meta. Tulloch announced his departure in a message to staff, and a spokesperson described his decision as driven by personal reasons. This move marks another high-profile talent shift in an AI sector where major firms are competing fiercely for the brightest minds.
Tulloch has an established history in the AI world: before co-founding Thinking Machines alongside Mira Murati in early 2025, he spent eleven years at Meta and had a stint at OpenAI. His return to Meta is seen as a major win for the company, which has been rebuilding and expanding its AI research teams under the umbrella of its recently formed Superintelligence Labs division. Meta’s aggressive recruitment campaign has already included major names like Scale AI’s co-founder Alexandr Wang and other top-tier AI figures as it seeks to intensify its competitive edge.
While the exact terms and team Tulloch will join at Meta haven’t been made public, reports suggest that his contributions at Thinking Machines were foundational. His exit is likely to affect the startup’s momentum, but the lab still holds onto a strong core, led by Murati and backed by a $2 billion seed investment that valued it at about $12 billion. For Meta, acquiring back someone with Tulloch’s insight and experience could accelerate its ambitions in AI, especially in areas like model fine-tuning, multimodal systems, and next-generation architectures.
