Anthropic has acquired one of the biggest players in the AI space.
Andrei Karpathy, a founding member of OpenAI and former director of AI at Tesla, announced Tuesday that he has joined Anthropic.
The hire is a major gain for Anthropic in the AI talent war. Karpathy is famous for coining the term “vibe coding” and is prolific in the AI community, often publishing long and widely read social media posts about the state of the industry.
“Personal update: I have joined Anthropic, and I think the next few years on the LLM front will be particularly formative,” Karpathy wrote about X. “I am very excited to join the team here and return to research and development. I continue to have a deep passion for education and intend to resume my efforts in education in time.”
Anthropic said Karpathy will work on the AI startup’s pre-training team, which will be responsible for large-scale testing of Claude. Karpathy joined the company this week and is part of a team led by fellow former OpenAIer Nicholas Joseph. He was an early employee at Anthropic, OpenAI’s biggest rival in the AI race.
“I can’t think of a better person to do this with. I look forward to building something together!!” Joseph wrote about X.
We are excited to welcome Andrej to the Pretraining team! He will be building a team focused on accelerating pretraining research itself using Claude. I don’t think there’s anyone better suited to do this. We look forward to building something together. https://t.co/mQb33SNiSW
— Nicholas Joseph (@nickevanjoseph) May 19, 2026
Karpathy’s AI roots go back to Anthropic’s main rival.
He helped launch OpenAI He then led the Tesla Autopilot computer vision team as AI Director at Tesla before returning to OpenAI in 2023. He publicly supported OpenAI CEO Sam Altman during his brief resignation, but ultimately left OpenAI again in February 2024 and subsequently founded the AI-focused education company Eureka Labs.
He became even more famous among the tech community in early 2025 when he coined the term “vibe coding,” which refers to “a place where you completely surrender to the atmosphere, embrace the exponential, and forget that code even exists.”
Vibe coding now shows how much even non-technically skilled users can create with the help of generative AI coding tools like Claude Code. Karpathy notes that AI models have recently advanced to the point where AI agents write the actual code themselves under the supervision of human users, necessitating a new terminology.
“Many people are trying to come up with a better name to distinguish this from vibecoding, my personal favorite right now, ‘agent engineering,'” he wrote in X in February.
Karpathy joins Anthropic at a time when the AI Lab is reaching new heights, thanks to significant advances in the company’s Claude Code and Cowork tools and widespread public interest following a standoff with the Trump administration. Anthropic’s secondary market valuation recently exceeded $1 trillion, surpassing OpenAI.
At the same time, the conflict between Anthropic and OpenAI has reached a fever pitch, with each CEO specifically refusing to hold hands on stage during photo ops with other AI leaders. OpenAI CEO Sam Altman recently accused Anthropic of inciting hatred against him and leading to the attack on his home.