You can't write a test first, obviously, because you can't test something that doesn't exist. It's obviously ludicrous.
But you change how you think about "a test" and it works just fine.
Surely this is suicide! They'll be disappointed and angry, and will not work with us! Except that this kind of feedback loop is commonplace now, and it works just fine.
When people work together, nothing is beyond them.
I think we have to check our incredulity at the door.
As we used to think, none of this could have happened.
We change how we think, and new vistas open up.
Who knows what is next?