💡 Writing Instructions That Still Hold After Context Compaction

Long Claude Code sessions eventually trigger context compaction — older conversation turns get summarised to make room for new work. Most of the time this is invisible, but instructions given casually early in a session ("also, never touch the migrations folder") can get lost or diluted in the summary if they weren't stated as a durable rule. The fix isn't to avoid long sessions — it's to put anything genuinely load-bearing somewhere compaction can't quietly drop it.

• Durable constraints belong in CLAUDE.md, not in a mid-conversation aside — compaction summarises conversation, it doesn't touch project memory files.
• Repeat critical constraints when they matter, not just when you first think of them — a one-line reminder before a risky operation costs little and removes ambiguity about whether the rule survived.
• Prefer explicit re-confirmation for destructive operations over trusting that an early-session caveat is still active forty turns later.

💡 Structuring Multi-File Refactors So Claude Checks Itself as It Goes

Large refactors that touch dozens of files are where agentic coding tools are most valuable — and where silent drift is easiest to miss if verification only happens at the very end. A more reliable pattern: break the refactor into checkpoints where Claude runs the test suite (or a narrower relevant subset) after each meaningful chunk, not just once at the finish line.