6. The four layers

For an application in use, the knowledge graph has four layers, and each layer is called an ontology: a structured description of one kind of knowledge. The Functional Ontology holds personas, outcomes, scenarios, steps and actions, and the Product Owner keeps it. The Design Ontology holds screen components and their building blocks, page templates and user flows, kept by the UX Designer and the design system owner. The Architecture Ontology holds services, boundaries, dependencies, data stores and integrations, kept by the Architect and the tech lead. The Code Ontology holds modules, classes, functions, endpoints and database schemas, kept by the Engineering Team. Links connect the layers, so one search can follow a user action through to the screen component, the service and the code function behind it. On one user story about email alerts, following those links found fourteen affected parts of the architecture and fifteen code changes across five repositories. The search runs before any code is written. Every item in the graph cites its source: the document, design frame, ticket or code file it came from.

On the site: The Four-Layer Ontology · Cross-Layer Traversal · Citations at Every Layer