IMHO integration tests are not there to validate the functionality that you're building - Kent is right here, if you rely on integration tests to find bugs, eit

IMHO integration tests are not there to validate the functionality that you're building - Kent is right here, if you rely on integration tests to find bugs, either your modules are either, or your design is bad (e.g. cross-module code paths that break encapsulation, etc). Integration tests are a god send when refactoring something that used to work in the first place. I'm currently switching 3rd party API providers in a system developed by somebody else long long time ago - all gritty corner cases need to continue working. The documentation is way outdated, especially the design docs. But, thankfully, the system has really good integration tests; so I'm super comfortable replacing modules one at a time, and knowing that functionality is preserved. Integration tests have their role, and, while they shouldn't be there to validate your building blocks, they should be there to validate that the customer is getting the functionality they're paying for.