Architectural Boundaries¶

Systems are divided by boundaries that separate concerns and allow independent development, deployment, or replacement of components

Tension Addressed¶

Consistency vs. Autonomy

Recognizable As¶

API layers; service interfaces; package/module boundaries; the line between "our code" and "their code"; plugin architectures; anywhere you could swap implementations

Canonical Sources¶

Martin, "Clean Architecture" (2017); Fowler, "Patterns of Enterprise Application Architecture" (2002)

Transfers To¶

Political Science (jurisdictional boundaries), Biology (cell membranes), Economics (firm boundaries), Physics (system boundaries)

Boundaries define what can vary independently. Well-placed boundaries isolate volatility. Poorly-placed boundaries force coordinated changes across teams or deployments.