Major layoffs shake up AI startup Thinking Machines

The ongoing competition in Silicon Valley for top AI talent intensified this week: three founders of Thinking Machines Lab, an AI startup led by former OpenAI CTO Mira Murati, announced their return to OpenAI. All three — Brett Zoff, Luke Metz, and Sam Shenhultz — previously worked at OpenAI before joining Thinking Machines.

Fiji Simo, head of applications at OpenAI, announced this on Wednesday. According to Simo, Zoff will report directly to her, while Metz and Shenhultz will report to Zoff. Zoff and Metz were co-founders of Thinking Machines, and Shenhultz was also part of the initial research and engineering team.

Disputes over layoffs
According to Core Memory, Murati informed employees of Zoff’s dismissal due to alleged “unethical behavior.” Neither Zoff, OpenAI, nor Thinking Machines commented on the situation. Simo noted that the hiring process took several weeks. Bloomberg reported that Simo told OpenAI staff that Zoff notified Murati of his intention to leave, after which he was immediately fired. Simo also dismissed concerns about Zoff’s behavior.

By Thursday, additional reports emerged that two more researchers from Thinking Machines — Leah Gai and Ian O’Connell — are also leaving the company, with Gai joining OpenAI. These high-profile departures highlight the challenges faced by new AI labs in retaining talent amid competition from giants like OpenAI, Anthropic, and DeepMind. Although some Chinese startups, such as DeepSeek and Moonshot AI, have developed competitive models, they are not competing for the same pool of specialists.