Spring task decomposition

Sizing rule

Each task is 1–4 hours for a competent engineer. If larger, split. If smaller than 30 minutes, fold into the previous task.

Shape

A good task has all of:

1. Stable ID T-NNN. Never renumber.
2. Linked AC-IDs — what user-visible criteria this task moves forward.
3. Test-IDs — at least one (T-NNN-T1, T-NNN-T2).
4. Files in scope — every path the task is allowed to edit (production + tests). The hook enforces this.
5. Dependencies — T-NNN IDs that must be done first.
6. Gates — which harness layers run for this task (default: all that touch the changed packages).
7. Rollback — one sentence on how to revert if validation fails.

Layering convention