Topic
Architectural Patterns
Recurring structures for system responsibilities and boundaries, including Domain Facades, Service Locators, Gateways, Data Managers, and Configuration Providers.
8 pages
Writing6 February 2022
Prefer Composition Over Inheritance
Composition keeps a configuration provider's capabilities limited to what its project needs. The refactor uses self-contained settings providers, a shallow base, and restrained reuse.
Writing20 December 2020
Validating Formal Arguments? No Thank You!
Validate and clean data at the front and back doors; skip checks on internal formal arguments. Immutable DTOs preserve trust, one exception reports all errors, and black box tests exercise the doors.
Writing5 December 2020
Separate State from Behavior? Yes Please!
Separating state from behavior simplifies object-oriented systems: immutable DTOs carry data, while managers compose collaborators and make operations explicit at call sites.
Writing21 September 2019
Interfaces? No Thank You!
C# interfaces do not inherently create contracts or loose coupling. Composition handles hierarchy conflicts; capability interfaces and structural typing let consumers see only what they need.
Writing11 August 2019
The Configuration Provider: An Abstraction With Roles and Responsibilities
A Configuration Provider hides the source, returns typed settings, validates required values, and reports useful errors. Composed providers let each system select its settings.
Writing20 September 2017
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.
Chapter20 September 2017
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.
Chapter20 September 2017
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.