[mceachen]

I think it's important that engineers can distinguish between testing code in isolation versus "integration" or "system" testing, but I've seen a sophomoric stigma around integration tests that lead to mocking hell, and a hatred towards testing in general.

Unit tests are great. You want them. Craft your interfaces to enable them.

Integration and system tests are important too. Again, crafting higher level interfaces that allow for testing will, in general, lead to a more ergonomic API.

Analogously: unit tests ensure each of your LEGO blocks are individually well-formed. Integration tests ensure that the build instructions actually result in something reasonable.