Why I Keep a Per-Project Investigation Log Outside Claude Code

After about six months of running Claude Code across multiple repos, I have stopped pretending that conversation history is enough.

I still use Claude Code for almost everything. The in-conversation layer is excellent for "what should I do next" and "explain this error". The problem is what happens after the conversation ends: I close the session, switch projects, come back two days later, and I cannot find the investigation I am sure I did.

I tried three fixes, and the one that stuck is a per-project investigation log that lives outside the chat.

The first attempt: rely on /resume and session IDs.