I'd don't understand how you can do "move fast and break things" without having unit tests. They seem pretty sine qua non to me, otherwise how do you know what's broken?
That said: tests are a development aid and a developer's friend and not an end in themselves. TDD can be a trap because without some code you won't really know what to test for. Better to write code/test couplets where the tests help you think through (and perhaps improve) the logic you've coded and then fix the implementation so that any breakages will be caught.
Biting the hand that feeds IT
