Claude Code Creator on Opus 5 and Prompt Overhaul

In a YC interview, Claude Code creator Boris Cherny revealed that the tool rewrote and deleted about 80% of its system prompts for Opus 5, while highlighting significant improvements in anti-prompt injection capabilities.

2026-07-26 ~ 2026-07-28 · 3 related posts

• Boris Cherny says Opus 5 resists prompt injection and Claude Code rebuilt most of its system prompt — ycombinator · 2026-07-26
• Boris Cherny explains how Claude Code cut 80% of its system prompt — Y Combinator · 2026-07-28

1 near-duplicate retellings: ycombinator