The hardest part of frontend testing isn't writing the test. It's getting the backend to return the exact response you need: a 500, an empty list, a malformed payload, right when you want it. On a live server that's painful, and sometimes impossible.
Here's the workflow I use instead. I make the app receive any response I want, without touching the backend at all. Postman mock servers do the heavy lifting, and an AI fills them with data.
The idea: a fake backend that looks real
Your frontend doesn't know where the JSON comes from. It calls a URL and trusts whatever comes back. So you point it at a mock server: a fake address that returns responses you defined in advance. Same endpoints, same shapes, zero real backend.
Why not just DevTools or a proxy?
