When building Python web apps, Firefox DevTools is underrated for debugging the frontend side. Specifically useful for Python devs: the Network panel shows all API calls with request/response bodies (great for debugging Django REST/FastAPI endpoints), CORS errors show up with specific header info, and the debugger has XHR breakpoints that pause execution when your JS calls any Flask/Django URL.

Also: Firefox’s Total Cookie Protection means your dev cookies don’t bleed across your dev/prod origins — useful when you have Django dev server on :8000 and prod at your domain.