The keep and its walls

Architecture is one decision made many times: what is allowed to depend on what.

Picture a keep. In the inner ring live your entities and use-cases — the rules that make your dApp yours: who may release funds, when a refund is owed. In the outer ring lives the changing world: the UI, the database, the chain SDK, the wallet.

The dependency rule is the keep's one law: source-code dependencies point inward, only. The outer ring may name the inner. The inner ring never — never — names the outer.