Hard agree. I don't know if "design doc" is the right word—I call them technical analyses—but writing up a doc that connects business & product needs to implementation details is highly useful to get everyone on the same page in terms of requirements & deliverables.
If I'm clear on the requirements & everyone else is clear on what I'm delivering, this is unnecessary. Sure, jump straight to prototyping. But this is rarely true for any serious project. There are always unknown unknowns that you need to tease out from the stakeholders, and a technical analysis is a great way to do that.
If I'm clear on the requirements & everyone else is clear on what I'm delivering, this is unnecessary. Sure, jump straight to prototyping. But this is rarely true for any serious project. There are always unknown unknowns that you need to tease out from the stakeholders, and a technical analysis is a great way to do that.