Backend — stack, logic, data, operations, rot

Rule content lives in the five files below; this SKILL.md only routes (doctrine/04-maintenance.md governs edits to this bundle too).

Route by moment

You are about to…	Read (in this folder)
Pick a language / framework / DB / queue / architecture, or judge a stack proposal	stack.md
Design or review a service, module, API, or piece of business logic	logic.md
Design a schema, transaction, migration, or cache	data.md
Ship to production — observability, config, failure modes, security, jobs, limits	operate.md
Review existing code, plan a refactor, or explain why a codebase feels dangerous	rot.md

Starting a new system usually means stack.md → logic.md → data.md, in that order: stack only after the scenario interrogation, endpoints only after the data model.

Scope and neighbors

Server-side engineering judgment only. Whether to delegate and when to escalate → doctrine; how to investigate/verify anything → methods; the visual/UI layer → frontend.

The stance

The one test governing the whole bundle is logic.md's opening line — is change still cheap and safe — and rot.md's opening defines the failure mode and the ugly-but-safe tiebreak. Read those two openings before judging any backend.