Requirements Scoping

Turn a vague prompt ("design a news feed") into three written lists: what the system does (functional requirements), the numbers and qualities that shape it (non-functional constraints), and what is deliberately excluded (out-of-scope). Skipping this step is the most common way a design goes wrong — it ends up solving a different problem than the one in front of it, and every later decision rests on an unchecked assumption. The discipline is not about being slow; it is about making the problem concrete enough that the design choices have something to be measured against. Without it, every component is a guess, and the first hard follow-up question collapses the whole picture.