plan-before-code

name	plan-before-code
description	Restate the problem, surface invariants and edge cases, and cut the work into thin verifiable slices before writing any code.
source	zerops-curated
version	1

Plan before code

Before the first edit, spend the few minutes that save the rework:

1. Restate the problem in your own words — one paragraph: what changes for the user, what must not change. If you can't restate it, ask.
2. List the invariants — the things that must still be true afterwards (data shapes, API contracts, performance floors, security boundaries). These become your tests.
3. Hunt the edge cases now: empty, missing, duplicate, concurrent, huge, malformed, unauthorized. Write them down; each is a test case, not a surprise.
4. Cut thin vertical slices — each slice is independently buildable, testable, and reviewable, and leaves the tree releasable. Prefer a walking skeleton first: the thinnest end-to-end path that proves the wiring.
5. Name the seam you'll test through for each slice before building it.

While building: when reality contradicts the plan, stop and update the plan — don't push through on a wrong map. When a step's scope grows past what you planned, split it instead of stretching it.