Karpathy joins Anthropic's pre-training team

Andrej Karpathy announced on May 19 that he had joined Anthropic. The short bio for anyone who's lost track: OpenAI cofounder, then Tesla's director of AI from 2017 leading Autopilot computer vision, then a brief return to OpenAI, then Eureka Labs — the AI education startup he had been running. Then Anthropic.

The role is the interesting part. Per TechCrunch, Karpathy is building a team focused on using Claude to accelerate pre-training research — the work that gives new models their core knowledge and capabilities in the first place. Not an applied team. Not an agent team. The team whose job is to make the next Claude train better than this one.

The hire lands while Anthropic is poised to surpass OpenAI's private-market valuation and in the middle of an unusually loud talent war between the two labs. Karpathy is the highest-profile name to switch sides this year, and the optics of an OpenAI cofounder running pre-training at the chief rival are doing their own work.

Practical read: this is the "models training models" loop showing up in a hiring decision. The same instinct that drives Cursor's Targeted RL with Textual Feedback or Composer 2.5's 25× synthetic-task expansion — using the current model to improve the next one — is now a staffing thesis at the lab level. If the bet pays off, the Claude that ships in 12 months won't just be a bigger Claude 4.7. It'll be a Claude trained by a Claude. Worth watching what shows up in Anthropic's research output over the next two quarters.