Nicely specced TTD style tests can show and then also verify that things work as you might expect them to. They can serve as example and documentation on how t

Nicely specced TTD style tests can show and then also verify that things work as you might expect them to. They can serve as example and documentation on how the architectural pieces fit together in a piece of software. That plus high level, loosely specced diagrams can encapsulate most simple/medium complexity apps.