Former OpenAI executive Mira Murati’s startup, Thinking Machines Lab, is losing two of its co-founders, both of whom are returning to OpenAI. An additional former OpenAI staffer who joined Murati’s startup is also headed back.
Murati announced the departure of co-founder and CTO Barret Zoph in a social media post on Wednesday. She stated that Soumith Chintala will become the new CTO, praising him as a brilliant and seasoned leader with over a decade of contributions to AI. Murati’s announcement did not mention co-founder Luke Metz or other departures.
Just 58 minutes after Murati’s post, OpenAI’s CEO of applications, Fidji Simo, announced that Zoph would be rejoining OpenAI. Simo also welcomed back Luke Metz and Sam Schoenholz, noting the moves had been in the works for several weeks.
Metz, a co-founder of Thinking Machines, previously spent several years on OpenAI’s technical staff. Schoenholz’s professional profile still lists him as working for Thinking Machines. Zoph was formerly OpenAI’s VP of research and, prior to that, a research scientist at Google for six years.
Murati, who was OpenAI’s CTO until September 2024, left and co-founded Thinking Machines with Zoph and Metz. As CEO, she has led the startup to significant financial backing, closing a $2 billion seed round last July. That round, led by Andreessen Horowitz with participation from Accel, Nvidia, AMD, and Jane Street, valued the company at $12 billion.
Reports indicate the split between Zoph and Thinking Machines was not amicable, a perception underscored by the brevity of Murati’s public message regarding his departure.
While talent movement between AI companies is common in Silicon Valley, the departure of co-founders from a startup less than a year after its founding is particularly notable. Losing two co-founders at once, including the CTO, could be seen as a meaningful setback for Thinking Machines, which had assembled a high-profile team from OpenAI, Meta, and Mistral AI.
The company has seen other key personnel depart, including co-founder Andrew Tulloch, who left to join Meta in October. OpenAI itself has experienced co-founders leaving for competing ventures, such as John Schulman, who left for Anthropic in August 2024 before joining Thinking Machines Lab as Chief Scientist at its launch last February.