Lilian Weng, co-founder of Thinking Machines, announced she would step down from her role citing health reasons. In an internal Slack message she wrote, “I don’t feel I’m able to continue at the pace a startup requires.” She also shared the message on X.
In the Slack post Weng said that after several months of consideration she had to admit the sustained stress and workload had become physically unsustainable: “After thinking about it for several months, I ultimately have to admit that the amount of consistent stress and workload have pushed me beyond what my health can sustain physically.”
Return to OpenAI
On Wednesday OpenAI told TechCrunch that Weng would be rejoining the company, where she previously served as the VP of AI Safety Research. According to a company spokesperson, Weng will lead a top-level team focused on accelerating OpenAI’s internal research. The spokesperson said the team will support cross-research work on areas including recursive self-improvement — a process that would allow an AI system to iterate on itself to become more powerful.
At first glance this move may seem to contradict Weng’s statements about the health impact of working at a fast-paced startup. However, she will likely face less direct pressure in a role where she is not a co-founder. The departure and quick return are notable amid fierce competition for talent among AI labs.
Reactions and further details
Thinking Machines co-founder and former OpenAI CTO Mira Murati replied to Weng’s X post earlier this week and expressed support for Weng’s decision to prioritize her health. Murati wrote: “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 Mira Murati knew that Weng would rejoin OpenAI. Beyond the announcement that Weng will lead a senior research-acceleration team, OpenAI has not provided additional public details about her exact role or day-to-day responsibilities.
