Ilya Sutskever, OpenAI’s co-founder and chief scientist who helped lead the infamous failed coup against Sam Altman and then later changed his mind, is officially leaving the company.

Both Altman and Sutskever have posts announcing the news:

Here’s Altman’s full post from X:

Ilya and OpenAI are going to part ways. This is very sad to me; Ilya is easily one of the greatest minds of our generation, a guiding light of our field, and a dear friend. His brilliance and vision are well known; his warmth and compassion are less well known but no less important.

OpenAI would not be what it is without him. Although he has something personally meaningful he is going to go work on, I am forever grateful for what he did here and committed to finishing the mission we started together. I am happy that for so long I got to be close to such genuinely remarkable genius, and someone so focused on getting to the best future for humanity.

Jakub is going to be our new Chief Scientist. Jakub is also easily one of the greatest minds of our generation; I am thrilled he is taking the baton here. He has run many of our most important projects, and I am very confident he will lead us to make rapid and safe progress towards our mission of ensuring that AGI benefits everyone.

Jakub refers to Jakub Pachocki, the company’s director of research, according to an OpenAI press release. It says he has been “spearheading the development of GPT-4 and OpenAI Five, and fundamental research in large-scale RL and deep learning optimization.”

The ambiguity around Sutskever’s employment following the Altman ouster last November spurred a meme: Where’s Ilya? What did he see? OpenAI cofounder Elon Musk has often take to the platform he owns, X (formerly Twitter), to pose the question himself.

The looming point is that if Altman was ousted temporarily from his own company because he was not “consistently candid in his communications,” does Sutskever know something the public doesn’t?

“I am excited for what comes next — a project that is very personally meaningful to me about which I will share details in due time,” Sutskever said in his statement on X.

Whatever happened, he seems to have represented a rift that has been growing inside OpenAI for some time. Jan Leike, who has been running the Superalignment team Sutskever stood up to “steer and control” more powerful AI, has also resigned from OpenAI, The Verge has confirmed. His responsibilities will be taken over by John Schulman, another OpenAI co-founder who sided with Altman during the failed board coup from last year.

Update May 14 7:55 PM EST: Added more details about Sutskever and the departure of Jan Leike.