Opus 5: Delete your CLAUDE.md?
Last week Y Combinator posted an interview with Boris Cherny, the engineer who built Claude Code, about the new Opus 5 release ( the full talk ). It was running in the background, and I was only half-listening right up until he told the room: ...delete your CLAUDE.md, delete your skills, delete your hooks... Whoa! What?! Let's rewind ... maybe I heard it wrong: ...for people that aren't building…
Last week, Y Combinator shared an interview with Boris Cherny, the engineer who created Claude Code, discussing the new Opus 5 release. During the conversation, Boris suggested deleting the CLAUDE.md, skills, and hooks for users who aren't building agentic products but are using Claude Code. He recommended trying this approach to see how the model performs, as it might surprise them.
This advice was based on the fact that Anthropic had reduced the system prompt in Claude Code by over 80% for Opus 5, as it was unnecessary due to the model's intelligence. The team at Anthropic used a process called ablation, which involves deleting the entire system prompt and then bringing it back line by line to determine the impact of each individual line.
The result was a compressed version of the instruction file that only included the essential instructions.
Written by urgent.news from Dev.to's reporting — not their text. Machine-written — may contain errors; check the original before relying on it.
