I despise it because I've seen some absolutely HORRIBLE designs that excessively separate concerns (that are actually linked and shouldn't be) in the name of "t

I despise it because I've seen some absolutely HORRIBLE designs that excessively separate concerns (that are actually linked and shouldn't be) in the name of "testability". I would rather maintain 50 lines of clear idiomatic code than 1000 lines of TDD code salad full of 3 line functions that each take a bunch of fragile mocks. It's also my experience that a few well written integration tests are more useful and catch more actual bugs than a million unit tests. This is especially true of web apps which are inherently highly stateful. The most powerful design paradigm I have ever found is to spend the first, say, 10-20% of my time making a rough prototype. Not with an eye of actually using a single line of it (although it happens) but just to do the quickest and dirtiest possible exploration of what the actual problem is.