This is how I test my code currently.

  1. Backend unit tests — fast in-memory tests that run the full suite in ~5 seconds on every save.                                                                 
  2. Full end-to-end tests — automated UI tests that spin up a real cloud server, run through the entire user journey (provision → connect → manage → teardown), and
   verify the app behaves correctly on all supported platforms (phone, tablet, desktop).                                                                            
  3. Screenshot regression tests — every E2E run captures named screenshots and diffs them against saved baselines. Any unintended UI change gets caught            
  automatically.

Check out exe.dev/Shelley web agent it facilitates much of what you describe by default.