Thinking Machines Lab CEO Mira Murati fired co-founder Barret Zoph after he and two others expressed discontent and sought more authority for Zoph.
Mira Murati's meeting with her co-founders was going off the rails.
Murati, the chief executive of AI startup Thinking Machines Lab, had shown up for work on Monday last week expecting to have a one-on-one with Barret Zoph, her chief technology officer, according to people familiar with the matter. Last summer, she had learned that Zoph was in a relationship with a colleague; in the months since, she had expressed repeated concerns about his lack of productivity, according to the people.
She was invited instead to an impromptu meeting with Zoph, another co-founder and a third employee. The three told her they disagreed with the direction of the company and that they were considering leaving.
They asked for Zoph to be given charge of all technical decision-making, according to the people. Murati responded that Zoph was already CTO and asked why he hadn't been doing his job for months, they said.
Two days later, Zoph was fired.
Within hours, all three had signed offers to rejoin OpenAI, the AI lab they had ditched a year ago to join Murati's fledgling startup.
The departures are a sign of how the heated AI race that is consuming hundreds of billions of dollars and transforming the economy is as much a battle for talent as technology. For all the high-tech advancements AI startups are sprinting to develop, they are ultimately at the mercy of the humans powering them.
Zoph's firing and decision to rejoin OpenAI with colleagues also marks a pendulum swing for a company that Murati, that startup's former technology chief, had founded with 20 former OpenAI employees.
Addressing Zoph's departure to Thinking Machines employees, Murati said there had been multiple issues with his performance, trust and conduct, according to an internal message viewed by The Wall Street Journal.
Zoph said she fired him after he expressed an intent to take a job elsewhere.
"Thinking Machines Lab terminated my employment only after it learned I would be leaving the company. Full stop. At no time did TML cite to me any performance reasons or any unethical conduct on my part as the reason for my termination and any suggestion otherwise is false and defamatory," Zoph said in a statement to the Journal.
The exits, coupled with fellow co-founder Andrew Tulloch's decampment to Meta Platforms last fall, leave Thinking Machines with just three of its original six founders.
Murati spent six years at OpenAI, where she earned a reputation for emotional intelligence and lack of ego, and was named interim CEO during the brief period when CEO Sam Altman was deposed. She helped launch its first product and ran almost every aspect of the company before starting Thinking Machines last February.
Many of the early researchers -- including Zoph -- that she hired came from OpenAI's post-training team. That division built ChatGPT and was tasked with teaching AI models how to communicate with humans. News Corp, owner of the Journal, has a content-licensing partnership with OpenAI.
Murati's issues withZoph started over the summer when she began to suspect that he was having a relationship with a colleague whom he had lobbied to bring over from OpenAI, according to people familiar with the situation. In responses to questions from the Journal, Zoph said many people at Thinking Machines wanted to hire the woman, including Murati.
At the time, Murati was in the process of raising one of the largest seed rounds in Silicon Valley history. The company ultimately raised $2 billion at a $12 billion valuation.
When she confronted Zoph about the possibility of an undisclosed relationship with a female employee who was junior to him at the company but did not report to him, he initially denied it, according to people familiar with the situation. By June, however, both Zoph and the woman had told Murati about the relationship, which had begun when they were colleagues at OpenAI, people with knowledge of those discussions said. The woman then left the company and returned to OpenAI.
Zoph told his boss that he had been manipulated by the woman into a relationship, according to people familiar with the matter. Shortly after that conversation, he took a break from work. When he returned in late July, Murati put him in a new technical contributor role with reduced executive and managerial responsibilities.
In his responses to the Journal, Zoph said it is common for technical managers to cycle back to doing technical individual contributor work to make sure they actually understand what is going on.
Over the next several months, executives at Thinking Machines witnessed a drop-off in Zoph's job performance, according to people familiar with the situation. For instance, his usage of Slack -- the main arena where the company did its work -- declined precipitously in the following months.
In his responses, Zoph said he worked as an individual contributor for two months and also worked on projects that included recruiting and retention of talent, road-map planning and the release of the company's model-training product, Tinker. He said he was also out of the office for parts of November and December due to illness and a death in the family, in addition to the holidays.
In October, shortly after Tulloch left for Meta, where he had worked previously,Zoph reached out to Altman to talk about coming back to OpenAI, he said.
By the time of their meeting with Murati last week, Zoph, co-founder Luke Metz, and the third employee, Sam Schoenholz, had been unhappy with the direction of the company for months, and had been holding talks with both OpenAI and Meta in recent weeks about joining either company as a trio, according to people familiar with the discussions.
In the meeting, the three voiced their disagreements with the direction of the company. They proposed that Murati, who held final say over technical decisions, assign that power to Zoph, including having one of the company's most senior executives report to him instead of Murati, according to people familiar with the details of the meeting. Murati expressed unhappiness with Zoph's productivity over the previous six months, some of the people said.
She asked whether they had already committed to jobs elsewhere. Metz and Schoenholz said they hadn't; Zoph didn't answer, some of the people said.
The day after the meeting, Zoph had dinner at a pizzeria with Meta executives Alexandr Wang and Nat Friedman, he confirmed.
On Wednesday, he was fired. Murati posted on X that Thinking Machines had "parted ways" with Zoph.
Less than an hour later, OpenAI's CEO for applications, Fidji Simo, posted that Zoph,Metz and Schoenholz were returning to the company and that negotiations had been under way for "several weeks." She said Zoph would report to her, while the other two would report to him.