OpenAI's new CEO once compared working for Microsoft to selling his soul. It'll now be his biggest investor.

• It doesn't sound like New OpenAI boss Emmett Shear was a fan of his time at Microsoft.
• Shear previously compared working at the tech giant to selling his soul in a post on X.

If Sam Altman needs advice on what working at Microsoft is like, he can ask Emmett Shear, the man who replaced him.

OpenAI's new boss previously said working at Microsoft, which has invested upward of $10 billion in the AI startup, was like selling his soul.

"When I was interning for Microsoft every paycheck felt like I was getting the payment for a little chunk of my soul in the mail," said Shear in a post on X, written in July. It is unclear how long or when Shear worked at the tech giant.

The Twitch cofounder was appointed interim OpenAI CEO on Sunday night, after negotiations to bring back Sam Altman fell through. In a post on X, he said the way Altman had been ousted was "handled very badly" and had "seriously damaged our trust."

His social media activity also suggests he has a relatively cautious approach to AI. In a post on X from September, he wrote that he was "in favor of slowing down" AI development.

Shear's comments on working at Microsoft are unlikely to help as he tries to smooth over the relationship between OpenAI and its largest investor.

Microsoft was reportedly given one minute's notice of Altman's firing, something which left Microsoft boss Satya Nadella "furious", an unnamed source told Bloomberg.

Nadella said that he "looked forward to getting to know Emmett Shear and OpenAI's new leadership team and working with them," in a post on X Monday in which he reaffirmed Microsoft's commitment to OpenAI.

In the same post, he said that Sam Altman and Greg Brockman would be joining Microsoft to head up a new AI team.

OpenAI and Microsoft did not immediately respond to a request for comment from Business Insider, made outside normal working hours.