Andrej Karpathy moved to Anthropic five weeks ago. That shift alone signals serious talent joining a leading AI safety lab, but the real news here is the Claude.md file one of his teammates shared. It’s a text prompt template that completely overhauls how Claude responds. Instead of the usual back-and-forth struggles, Claude now locks onto your instructions from message one. The file lays out clear rules, formatting guidelines, tone settings and error-handling steps. You feed Claude.md into the model at the start of your session, and you get consistent, on-target answers—no more vague or evasive replies. My friend reports faster, more precise outputs on coding tasks, research queries, even creative writing prompts. Karpathy’s presence at Anthropic suggests they’re doubling down on model alignment and user control. Giving everyone access to this kind of prompt blueprint could redefine best practices for interacting with large language models. Bookmark that file now—if it disappears, you’ll have to scramble to rebuild those same instructions from scratch. Next, check out the linked article for a deeper dive into Claude’s new prompt architecture and Anthropic’s broader strategy post-Karpathy. It’s the clearest look yet at how small changes in prompt design can unlock major productivity gains.