A project usually starts with a list of basic looking cosmetic bugs that the stakeholder is having a hard time getting Claude to fix. Literally every bug unearths a heap of other bugs or architectural problems.
As an example yesterday I was looking at a basic, “record XYZ not appearing on list view” bug. Turned out that Claude had built the list view (which should have been backed by thousands of records) to only ever load the first 100, and then do all organization, counts, sorting and filtering on the frontend on that dataset.
Also found a query that was taking ~18 seconds to query 1 record from a set of ~60.