The word you're looking for is "prototyping". I'm not being sarcastic (well, okay, a little), I pretty much agree with most of what you wrote (of course depend

The word you're looking for is "prototyping". I'm not being sarcastic (well, okay, a little), I pretty much agree with most of what you wrote (of course depending on the project at hand), except the notion that this is something new. Also, just working on the front-end/user experience doesn't give you, and certainly not the back-end developers, a "solid foundation of domain knowledge". That only happens if they are deeply involved in the same process, and front-end-first suggests exactly the opposite. A front-end, no matter how wonderful and detailed, is still way to vague to serve as specs unless the application is very simple.