Thanks for taking the time to reply. Yeah ideally we always use real resources to mirror prod closely, but I see your point that that won’t always be possible as the app grows.
Another balance is to just use real resources in CI with some concurrency control to make sure a single build runs at once. Locally, you continue to use mocks/stubs/fakes
You still get assurance from testing but reduce the amount of places you run the "expensive" (time, resource, $) tests
You still get assurance from testing but reduce the amount of places you run the "expensive" (time, resource, $) tests