Two Thinking Machines Lab Cofounders Are Leaving to Rejoin OpenAI

City: San Francisco: Two cofounders from Thinking Machines Lab, Barret Zoph and Luke Metz, are leaving the startup to rejoin OpenAI. This news was announced on Wednesday by OpenAI’s CEO of applications, Fidji Simo, in a memo to staff.

There are two stories about why they left. A technology reporter named Kylie Robison tweeted that Zoph was fired for “unethical conduct.” Some say he leaked secret company information to rivals. WIRED has not confirmed this with Zoph, as he did not reply to their questions.

On Monday, Zoph told Thinking Machines CEO, Mira Murati, that he might leave. He was then fired on Wednesday. In her memo, Simo said that OpenAI does not share the same worries about Zoph as Murati does.

This change is big for OpenAI, which recently lost another top staff member. A third employee from Thinking Machines, Sam Schoenholz, is also heading back to OpenAI. This will hurt Thinking Machines, which lost another co-founder, Andrew Tulloch, to Meta last November.

Murati confirmed Zoph’s departure on social media, saying Soumith Chintala will take over as chief technology officer. Zoph and Metz had left OpenAI in late 2024 to start Thinking Machines with Murati, who was OpenAI’s former chief technology officer, leading projects like ChatGPT.

Simo told her team that Zoph would report directly to her, while Metz and Schoenholz will work with him. They are still sorting out specific job details.

Thinking Machines is one of several AI startups led by past OpenAI workers. Last year, the company was valued at $12 billion and discussed raising over $4 billion at a value of $50 billion. Their main product is Tinker, which lets developers tailor AI models to their own datasets.