One can enforce the use of TDD through pair programming with rotation, as Pivotal does. I don't know that Pivotal (in particular) does pair programming so that

One can enforce the use of TDD through pair programming with rotation, as Pivotal does. I don't know that Pivotal (in particular) does pair programming so that TDD is followed, I do know that they (did) follow TDD and do everything via pair programming. I'm agnostic as to whether it's a good idea generally, it's not how I want to live but I've had a few associates who really liked it.