Thinking Machines co-founder Lilian Weng leaves, then joins OpenAI

In short: Lilian Weng left her role as a co-founder at Thinking Machines for health reasons and then rejoined OpenAI.

What happened

Lilian Weng, a co-founder of the AI startup Thinking Machines, said this week that she is stepping down from her role due to health issues. In an internal Slack message that she later shared on X, Weng wrote that she could not continue “at the pace a startup requires.” She said the stress and workload had pushed her beyond what her health could sustain.

On Wednesday, OpenAI confirmed to TechCrunch that Weng is returning to the company. Weng previously worked at OpenAI as the VP of AI Safety Research, which is a role focused on reducing risks from powerful AI systems.

OpenAI said Weng will lead a senior team aimed at speeding up the company’s internal research. The team will support work on “recursive self-improvement,” which OpenAI describes as an approach where an AI system helps improve itself over repeated cycles (like a student who can also rewrite the textbook and make it better each time).

Thinking Machines co-founder Mira Murati publicly replied to Weng’s post on X with support for her decision to focus on her health. It is not clear whether Murati knew Weng would soon join OpenAI.

Why it matters

Top AI labs compete hard for experienced researchers, and high-profile job moves can shift what these companies work on and how fast they move. Weng’s comments also highlight a broader issue: startup jobs can demand long hours and constant pressure, which can affect people’s health.

Source: TechCrunch AI