Design Change Policy

Design is allowed to change — but only through a controlled flow. The forbidden shortcut is:

discover problem → change code → leave docs stale

Foundry's rule: Code must never stay ahead of Docs. An emergency experiment may provide short-term verification, but it must not be delivered as the final implementation before the sources of truth are synchronized.

The standard flow

Impact levels

Level	Scope	Trigger examples	Must update
L1	Feature-local	A change within one Feature	Current Spec, Test Design, necessary API / Database / UI
L2	Cross-Feature	Multiple Features, a shared contract, Roadmap, Design System	Related Specs, API, DATABASE, UX/UI, DESIGN_SYSTEM, ROADMAP, Tests, necessary Architecture
L3	Architectural	Module boundary, major tech choice, Source of Truth, messaging, cache, authentication, DB strategy, frontend architecture, global navigation, Design System core, API style, consistency model	Every truly affected document + ADR, plus related Specs, AGENTS, Tests

Only genuinely affected documents are updated — never extra files to make the change look comprehensive.

Authority requirements

• L1 — a named Decision Authority empowered for that Feature confirms any change to approved Scope, AC-*, an external contract, observable behavior, or user-visible copy. L1 describes impact scope only; it is not automatic authorization.
• L2 — named Decision Authorities for all affected Features confirm scope and choice; if unconfirmed, STOP.
• L3 — a named Architecture Decision Authority confirms the decision. An ADR records Context, Decision, Alternatives, Consequences, the authority, and the decision revision.

For L3, coding may resume only after the ADR reaches the project's implementation-authorizing state (for example, Accepted or Effective).

Downstream gates go stale

A Design Change marks affected gates STALE through the invalidation chain, and they must be re-validated before work resumes. See Workflow & Gates for the chain.

Not a Design Change

A reversible implementation refinement that changes no requirement, contract, or observable behavior is not a Design Change — it updates only the Implementation Plan.