How are you mocking APIs during frontend development today?

I’ve tried a lot of workflows over the years:

• editing local JSON files

• hardcoding mock states

• running proxy tools

• setting up mock servers

• intercepting requests with external apps

But I still felt the workflow was slower than it should be — especially when debugging edge cases like:

• empty states

• failed requests

• slow APIs

• malformed payloads

• role-based responses

Most solutions either require backend changes, extra setup, or switching context away from DevTools.

So recently I started experimenting with a Chrome DevTools-based approach where API responses can be overridden directly inside the browser during runtime.

The interesting part for me wasn’t the extension itself, but the workflow change:

• no proxy setup

• no local server

• no backend dependency

• instant response overrides while inspecting requests

I’m curious how other developers here handle API mocking and response testing in daily work.

What’s your current workflow?
What tools are you using?
And what’s the most annoying part of testing frontend states today?

(For context, this is the prototype I’ve been experimenting with:
https://chromewebstore.google.com/detail/network-overrides-api-dev/holdjgmcnpelgclhopiejilhhkfcmpba )