Write the spec. Write the tests. Write the code. I'm taking about API and system level tests. Unit tests vary in scope between 'test a function' and 'test a

Write the spec. Write the tests. Write the code. I'm taking about API and system level tests. Unit tests vary in scope between 'test a function' and 'test a unit interface'. Former should be done by the dev during development. Latter should be done by someone else. It's a grey area between those extremes. I'm coming from a systems programming and embedded background so I have no idea if a web dev or someone else should follow my advice, but I suspect so.