Andrej Karpathy joined Anthropic on 19 May 2026 to lead a new team using Claude to accelerate pre-training research, reporting to Nick Joseph, Anthropic's head of model development, according to TechCrunch and Bloomberg. The hire closes a 22-month chapter in which Karpathy ran Eureka Labs, an AI-native education startup, as an independent founder rather than a frontier model researcher. In a post on X on 19 May, Karpathy wrote: "I think the next few years at the frontier of LLMs will be especially formative. I am very excited to join the team here and get back to R&D."
What Andrej Karpathy built at Eureka Labs, and why he paused it
Karpathy founded Eureka Labs in July 2024, registering the Delaware LLC on 21 June 2024, per VentureBeat. The model was an "AI-native school": real human-designed curriculum delivered through an AI teaching assistant that guides each student individually through the material. The concept drew on Karpathy's history as a Stanford lecturer, but the product was designed to scale without him in the room.
Eureka Labs closed approximately $20 million in seed capital in early 2025, with investors including Conviction's Sarah Guo and Sam Altman. The company's flagship product was LLM101n, an undergraduate-level course guiding learners through building a "Storyteller AI" large language model from scratch in Python, C, and CUDA, per Bloomberg's July 2024 coverage. The GitHub repository for LLM101n accumulated more than 36,000 stars by August 2024 before Karpathy archived it as read-only on 1 August 2024, signalling a shift toward product development over open publication. A second release, "nanochat," arrived in October 2025 as a minimal from-scratch ChatGPT demonstration.
Product output remained limited across the company's 22-month lifespan. In his departure post, Karpathy did not describe Eureka Labs as closed; he said he "remain[s] deeply passionate about education and plan[s] to resume my work on it in time," per TechCrunch.
The year AI made Karpathy feel behind
Two public appearances in early 2026 reveal how Karpathy's working patterns had already shifted before the Anthropic move. On the No Priors podcast, reported by Fortune on 21 March 2026, he described reaching a state he called "AI psychosis": a persistent anxiety about falling behind the frontier of what AI agents could accomplish. "I'm just like in the state of psychosis of trying to figure out what's possible, trying to push it to the limit," he said. The immediate cause was a coding inflection point he traced to December 2025. "I don't think I've typed like a line of code probably since December, basically, which is an extremely large change," he told No Priors. Earlier in 2025 he estimated he was personally writing around 80% of his code, with AI agents handling the remaining 20%; by December that ratio had inverted to roughly 20% human, 80% agent.



