Thinking Machines had been founded by former OpenAI CTO Mira Murati and other senior OpenAI researchers, but many of these researchers seem to be heading back to OpenAI.
Barret Zoph, who served as CTO and co-founder of Thinking Machines, has departed the AI startup and returned to OpenAI, along with two other senior researchers, Luke Metz and Samuel Schoenholz. The moves represent a possible blow to the young company, which was founded just months ago in 2025 by former OpenAI executives.
“We have parted ways with Barret Zoph,” said Mira Murati, co-founder and CEO of Thinking Machines, in a statement. “Soumith Chintala will be the new CTO of Thinking Machines. He is a brilliant and seasoned leader who has made important contributions to the AI field for over a decade, and he’s been a major contributor to our team. We could not be more excited to have him take on this new responsibility.”
The departure of Zoph, Metz, and Schoenholz means that half of Thinking Machines’ six-person co-founding leadership team has now left the company within its first year of operation. According to company materials, the original founding team included Murati, John Schulman, Zoph, Lilian Weng, Andrew Tulloch, and Metz as co-founders.
Fidji Simo, CEO of Applications at OpenAI, announced the returnees on social media, writing: “Excited to welcome Barret Zoph, Luke Metz, and Sam Schoenholz back to OpenAI! This has been in the works for several weeks, and we’re thrilled to have them join the team. Barret will report to me; Luke and Sam will report into Barret. More to come on what they’ll focus on soon!”
Kylie Robinson of Core Memory reported that Barret Zoph had been “terminated” for leaking confidential information to OpenAI. “Thinking Machines has terminated its CTO, Barret Zoph, due to unethical conduct according to two sources familiar with the matter. CEO Mira Murati announced the news at an all-hands with employees today,” she reported. Wired also added that In a memo to staff, FIdji Simo said the OpenAI doesn’t share Murati’s ethical concerns over Zoph’s actions.
The three returning Thinking Machines researchers bring significant AI expertise back to OpenAI. Zoph previously served as VP of Research, Post-Training at OpenAI from September 2022 to October 2024, following nearly seven years at Google Brain where he worked as a research scientist. Metz spent over two years at OpenAI as a member of technical staff before joining Thinking Machines in late 2024, while Schoenholz had a two-year stint at OpenAI and previously worked as a senior research scientist at Google.
Thinking Machines was founded in February 2025 and was valued at $12 billion after raising $2 billion in its seed round. The company was founded by former OpenAI CTO Mira Murati after she was a part of a failed coup to dislodge OpenAI’s CEO Sam Altman and President Greg Brockman. Thinking Machines hasn’t yet released a public product, but has shared some research around AI development. And with half its founding team now leaving in less than a year of its founding, the company will have to regroup and look to executive on its vision in the rapidly-changing AI space.