What's wrong with Test Driven Development?

We don’t use it company wide, but I definitely know individual developers who practice TDD with the full red/green/refactor while they work on their stories. You can definitely see a difference in the code and tests of developers who do this when reviewing code.

As for why you don’t see broader adoption, I think the main blocker is that it’s a paradigm shift and it takes a lot of discipline. Most people like to tinker and get things working, and then go back and polish it up. TDD requires one to really think ahead of time about what they’re doing and approach it super linearly, rather than twisting a dial here or flipping a switch there till everything works.