Writing
Abstraction in Software Design
Useful abstractions express the caller's needs precisely. Broker, database and charting examples show where SDK types, storage details and excess generality get in the way.
Topic
Public Surface
The set of types a component exposes to its callers. Everything a caller can receive, pass or must catch belongs on it, and everything else stays internal, so the interior can change without breaking anyone.
7 pages
Writing
Dependency Injection? No Thank You!
Dependency injection exposes private collaborators to callers when used for every internal relationship. Keep classes self-contained and let business code choose real variation.
Writing
Extension Methods? No Thank You!
Keep project-specific helpers as static methods: extension methods hide behavior behind namespaces and can change meaning with imports. Use them when they serve the wider C# community.
Writing
Clean Abstractions Around Libraries
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
Architecture Layers in C#
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
Architecture Layers in Python
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
Architecture with Intent
The Domain Facade exposes business operations while internal classes call one level down. Managers orchestrate workflows and own configuration and service boundaries.