Thinking Machines Lab keeps losing employees back to OpenAI

An employee who joined Thinking Machines Lab in April 2025 after three years at OpenAI has returned to OpenAI. She follows several co-founders and researchers from the lab who departed in recent months, with others leaving for Meta. Thinking Machines Lab raised $2B at a $12B valuation but is hemorrhaging talent to larger competitors. The exodus raises questions about retention at well-funded AI startups competing against the resources and brand of frontier labs.

View full digest for February 21, 2026