Beyond signup and checkout, my app has a handful of things users actually do. I want end-to-end tests covering those core flows. First, ask me (or infer from my routes and UI) what the three to five core user flows are. For example: create a thing, edit a thing, share a thing, invite a teammate, export data. Confirm the list with me before writing tests. For each confirmed flow, write a browser-level test that: 1. Logs in as a fixture user (reuse my test account setup or fixtures if they exist). 2. Walks the flow exactly as a user would, through the real UI. 3. Asserts the end state both in the UI and, where it matters, in the database. 4. Includes one negative case per flow where it makes sense: deleting something that shouldn't be deletable, submitting an empty required form, exceeding a limit. Keep each test independent. No test should depend on another test having run first. Each one creates its own data and cleans up, or runs against a reset test database. Don't chase pixel-perfect assertions or test copy text that changes often. Assert on structural things: the record exists, the button state changed, the item appears in the list. Brittle tests get deleted. When finished, run the suite and report pass/fail per flow, plus how long the full suite takes to run.