TDD is about creating tests for your requirements, and then writing code to make them succeed. The reason it doesn't work is because most medium/large feature c

TDD is about creating tests for your requirements, and then writing code to make them succeed. The reason it doesn't work is because most medium/large feature changes don't fully realize their scope and requirements until they're well along into development, making the earlier tests an unnecessary drag. Writing unit tests at all is independent of TDD. After you get the feature working, you write those to verify the program does what you think it does and to think through failure scenarios. Most importantly they make sure that future changes do not break the functionality you just implemented. I think asking for unit tests is important for any true bit of functionality in a large system.