Chapter Four

Knowing What to Build: Requirements & Product

Before anyone designs or writes a thing, someone has to figure out what the software should actually do — and that knowledge starts scattered and fuzzy. This chapter is about turning vague wishes into clear, buildable work: where requirements come from, the two kinds of them, how teams capture them as user stories, and the discipline of building the smallest useful thing first.

4 topics

The most expensive mistake in software isn't a bug — it's building the wrong thing well. A flawless app that solves a problem nobody has is a total loss. This chapter is the defense against that, the "requirements" phase from the lifecycle up close.

Four topics. First, where requirements even come from, and why the customer rarely hands you the answer. Then the crucial split between what software must do and how well it must do it — the part beginners forget. Then how Agile teams capture requirements as short, human-centered user stories. And finally the art of scope: shipping the smallest useful version first, and ordering everything else.

From a fuzzy wish to buildable work
A vague wish
"people should stick to their habits better"
A discovered need
"users forget to check in each day"
A user story with acceptance criteria
"remind me daily, at a time I choose"
Prioritized in the backlog
a clear, ready, buildable piece of work

Topics in This Chapter