The Recursive Turn: Andrej Karpathy Joins Anthropic's Pretraining Team
·7 mins
On May 19, 2026, Andrej Karpathy posted seven paragraphs to X announcing he was joining Anthropic. The post crossed 148,000 likes within a day, and someone on tech Twitter compared it to Kevin Durant joining the Warriors — the sport’s best individual player walking onto the roster that was already winning.
Karpathy’s own framing was quieter: “I think the next few years at the frontier of LLMs will be especially formative… excited to join the team here and get back to R&D.” He would lead a new pretraining-research group under Nick Joseph, Anthropic’s head of pretraining, built around a premise with a slight vertigo to it: use Claude to help build the next Claude.