System & Capability Modeling

The architecture overlay's supply side: the capabilities a product can do (the engineering primitives), the systems that provide them, the features that package them for consumption, and the UI surfaces that expose them. Every example is a real construct from the Chowk marketplace.

Overview
- The architecture overlayDomain and application modeling describe how the system is built — the aggregates, the commands, the events. The architecture overlay describes what the system is, as a product: the capabilities it…
The capability layer
- CapabilitiesA capability is the overlay's first-class engineering primitive: a durable, implementation-independent statement of what the system can do. It is what you build, what a business process requires, and…
System structure
- SystemsA system is a node in the architecture map. A capability system is a logical unit of product value that provides capabilities; an infrastructure system is a concrete piece of the stack — a database,…
- Composition & roll-upsSystems relate to each other in two structurally different ways, and the overlay keeps them sharply distinct: composedof — CONTAINS. A parent system is made of its children. This is the tree the…
Features & access
- FeaturesA feature is the overlay's business construct: a way to package capabilities for consumption. Where a capability is the engineering primitive — what the system can do — a feature is how that…
- UI surfacesA ui surface is the overlay's access side: a concrete interface deliverable through which a persona reaches a capability. A screen a customer clicks, the REST API a client calls, the event stream a…