3 sessions on dompurify with a coding agent: the agent failed at least once in 0, and 2 finished without a human stepping in.
Takeaway: Next time I'd point straight at the file using beautiful-mermaid instead of just saying 'fix pnpm check:web' — the agent spent a lot of turns reading through MarkdownRenderer.svelte before it found the real issue, that the code was written for classic mermaid.js but imported a completely different library.
Takeaway: Next time I'd ask upfront for the revert plus a rebuild/lint check in one go, since resolving the three-way conflicts in package.json, the lockfile and the component took most of the turns.
Takeaway: I'd start by pointing out the uncommitted package.json/pnpm-lock.yaml changes myself so the agent doesn't have to pause and ask — that stop-and-ask was reasonable but cost time I could've saved with more context up front.