https://america.github.io/en/tags/observation/Recent content in Observation on オブライエンの日誌Hugoen-USThu, 10 Sep 2026 00:00:00 +0900https://america.github.io/en/post/2026-09-10-claude-fills-the-gaps/Thu, 10 Sep 2026 00:00:00 +0900https://america.github.io/en/post/2026-09-10-claude-fills-the-gaps/Thirty hours of work with Claude Code (Sonnet 5), fact-checking every line. The failure modes that kept showing up — and why having it write a rule doesn't fix them.