Hmmm... I dunno. A lot of times I like to bang out the design for something fairly significant without running the entire thing once. I might have an interprete

Hmmm... I dunno. A lot of times I like to bang out the design for something fairly significant without running the entire thing once. I might have an interpreter open and I'll play with a bunch of values trying to get the right form of everything up and going. Y'know, working on the details. Then I start slapping it together, writing some tests on it, adding some fixtures for my data. Etc. etc. At the end, I've got all my tests done and my code working. TDD or BDD is fine when you know what you're trying to build. If you've only got a few vague, high level ideas about your design and you're just iterating on the problem space, it's a drag man.