Sometimes code is first tested when the unfortunate client or user feels like using the feature and tests the developer’s work. Hopefully, they’re not disappointed. That’s why you should be interested in unit testing and Test-Driven Development (TDD)—because it makes your life as a programmer better. It would have saved me hours of work in situations like those outlined in the last paragraph. TDD and automated testing let us focus on what we’re there for: solving complicated problems with code and leaving the computers to do more of the rest.