System design lifecycle

Own system boundaries, runtime interfaces, operational data stores, system migrations, and architecture decisions. Do not equate a diagram, SQL file, or OpenAPI document with a working, safe, or scalable system.

Read references/system-design-resource-map.md before any existing-system task. It defines the lifecycle, artifact contract, decision stop, evidence states, access tiers, and cross-skill ownership. Read references.md only for the database/API/reliability branch that applies to the selected system.

Non-negotiable boundary