Thinking Machines loses two co‑founders as researchers return to OpenAI

Thinking Machines Lab, the startup launched by former OpenAI executive Mira Murati, has lost at least two co‑founders who are returning to OpenAI, a rapid personnel shift that reshapes leadership at a company still in its infancy. Murati posted on X that co‑founder and chief technology officer Barret Zoph had “parted ways” with the company and that Soumith Chintala, whom she described as “a brilliant and seasoned leader,” would assume the CTO role.

Shortly after Murati’s announcement, OpenAI’s chief of applications, Fidji Simo, publicly welcomed Zoph back to the company and confirmed that fellow Thinking Machines co‑founder Luke Metz and researcher Sam Schoenholz were also joining OpenAI, saying the moves “had been in the works for several weeks.” The sequence of public posts unfolded quickly and leaves open questions about timing and internal negotiations.

Zoph had been serving as Thinking Machines’ CTO after leaving OpenAI, where he previously held the role of vice president of post‑training following an earlier stint as a research scientist at Google. Metz was a technical staffer who contributed to projects including ChatGPT and OpenAI’s o1 reasoning model. Schoenholz is a researcher who joined Thinking Machines after work at OpenAI. Murati, who left OpenAI in September 2024 to found Thinking Machines with Zoph and Metz, now faces the loss of two founders and a change in technical leadership less than a year after the startup secured substantial early backing.

An internal OpenAI memo circulated by Simo reportedly said Zoph told Murati he was considering leaving and was subsequently fired. Separate, unverified allegations have appeared that Zoph shared confidential company information with competitors; those claims have not been independently confirmed, and Zoph did not immediately respond to requests for comment. Thinking Machines has not released detailed public statements about the circumstances beyond Murati’s post naming Chintala as CTO.

The departures represent a material disruption for Thinking Machines. Losing two high‑profile co‑founders and the CTO role could alter engineering priorities, product timelines, and investor confidence at a moment when the company’s roadmap is still being established. Public commentary and social posts have referenced large early financing and ambitious valuations for Thinking Machines, with figures circulating widely; those reported amounts vary and have not been independently verified.

For OpenAI, the returns amount to a consolidation of research talent as the company seeks to stabilize its workforce following its own departures and transitions. Bringing back researchers familiar with OpenAI’s codebase and strategy may accelerate ongoing projects, but it also deepens the concentration of senior AI talent in one organization at a time of intense competition among well‑funded rivals.

Key questions remain unanswered: the contractual terms and timing of the moves, whether any confidentiality or noncompete issues are at play, and how Thinking Machines will adjust its technical plan and investor communications. Soumith Chintala’s appointment provides immediate leadership continuity at the technical level, but the startup’s ability to retain remaining staff and maintain momentum will be watched closely by investors, partners, and competitors as the companies recalibrate in the weeks ahead.