An experiment in AI-assisted development — from a simple checklist idea to a categorised daily tracker with a Playwright test suite, entirely through incremental prompting.

When an API project needs to change its data source without the customer noticing, unit tests are not enough. This is the story of how I built a custom comparison pipeline to close that gap — alone, incrementally, and with a little help from ChatGPT.

How I went from idea to working MVP in a single evening — and why the 90 minutes was the easy part.