Lilian Weng Leaves Thinking Machines, Rejoins OpenAI
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- Lilian Weng announced her departure from Thinking Machines this week, writing in an internal Slack message shared on X that "consistent stress and workload have pushed me beyond what my health can sustain physically."
- OpenAI told TechCrunch on Wednesday that Weng, who previously served as VP of AI Safety Research, would rejoin to lead a top-level team focused on accelerating the company's internal research.
- Weng's new team will specifically support cross-research work on recursive self-improvement, a process by which an AI system iterates on itself to become more powerful.
- Mira Murati, Thinking Machines co-founder and former OpenAI CTO, responded to Weng's X post with support: "We'll miss you, it's been wonderful building Thinky together. I'm glad that you're putting your health first. Thank you for everything."
- It is unclear whether Murati was aware that Weng would rejoin OpenAI when she posted her supportive message, making the warm public exchange an awkward backdrop to a direct talent loss.
- The move comes "in a time of fierce competition for talent among AI labs," per the source, and removes one of Thinking Machines' named co-founders as the startup continues to build out its team.
Why it matters: Weng's departure strips Thinking Machines of a named co-founder at a moment when AI labs are locked in fierce competition for top researchers, while OpenAI regains a former VP of AI Safety Research to lead work on recursive self-improvement — one of the most consequential and contested research directions in the field.
