# The Cathedral Principle

Build commerce infrastructure in durable layers: identity, tenant isolation, payments, operations, analytics, then automation. Each layer should make the next layer safer to scale.

Use this brief as a planning worksheet:

1. Name the layer you are improving this quarter.
2. List the manual decisions that still block scale.
3. Add a rollback or kill switch for every new mutation.
4. Define the metric that proves the layer is stable.