One of xAI's cofounders has joined Anthropic following its purchase of all of the Colossus data center's compute.

Ross Nordeen said that he was joining Anthropic "to focus on compute," as the company looks to rapidly expand its data center infrastructure amid rate limits and outages.

"Incredibly proud of the xAI team's execution in bringing on an immense amount of compute so quickly and couldn't be more excited for Elon [Musk]'s vision of an abundant future w/ intelligence spreading to the stars," Nordeen said.

"Over the past weeks, I've had the pleasure of getting to know the team at Anthropic and [we] share a similar vision."

Nordeen quit xAI earlier this year, the last co-founder to leave the company other than Musk. Eleven cofounders quit ahead of its merger with SpaceX, as well as around 80 staff members.

Following the mass departures, Musk claimed that xAI “was not built right first time around” and is now “being rebuilt from the foundations up.”

The company's chatbot Grok has faced declining usage, while the company has leased compute capacity to Cursor and now rival Anthropic. Under SpaceX, the company has plans to deploy compute in space - with the two firms set to be known as SpaceXAI - but timelines remain unclear.

Prior to his three-year stint at xAI, Nordeen spent another three years working on supercomputers at Musk's Tesla business. He has also worked at Handshake, Palantir, and Whamcloud, as well as internships at Los Alamos and Sandia national labs.