
Writing
Learning a System Through Its Tests
Acceptance tests let teammates learn requirements and production behavior together. Follow one order through Arrange, the visible Act, independent observations, and complete assertions.

Topic
How a system is divided into layers, where each responsibility belongs, and what may legitimately depend on what.
11 pages

Writing
Acceptance tests let teammates learn requirements and production behavior together. Follow one order through Arrange, the visible Act, independent observations, and complete assertions.

Writing
A stable Domain Facade lets acceptance scenarios and assertions survive internal refactoring. Adapt test support behind unchanged observations and adopt complete boundary tests feature by feature.

Writing
Dependency inversion needs domain-owned contracts that hide implementation knowledge. Follow a show query from source dependencies through models to a stored procedure.

Writing
Specific exceptions preserve failure meaning, causes, and context. A shallow C# hierarchy, Gateway translation, and middleware enrichment carry diagnostic records across service boundaries.

Writing
Structured logs preserve the facts needed to investigate failures. Application Insights custom dimensions make them searchable, while typed progress events track long-running work.

Writing
A library boundary owns the application's contract even when its terms match the library's. It contains provider types, validation, failures, and configuration, and keeps replacement possible.

Chapter
Structure communicates intent: strict layers from Domain Facade to Gateway, internal by default with a public surface the compiler enforces, and folder depth that marks each class's level of abstraction.

Chapter
Structure communicates intent: strict layers from Domain Facade to Gateway, a public surface declared in the boundary __init__.py, and folder depth that marks each class's level of abstraction.
PWI
The Domain Facade exposes business operations while internal classes call one level down. Managers orchestrate workflows and own configuration and service boundaries.

Writing
A Data Access Layer isolates business logic from the logical data model through domain-specific methods, stored procedures, and results shaped for the business layer.

Writing
ASP.NET MVC's indirect access to views spreads responsibilities across controllers and templates. ViewData, child actions, and typed view instances frame the critique.