Writing
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.
Topic
Configuration Provider
A typed wrapper over raw configuration that reads and validates settings eagerly and returns typed settings objects. Only the Manager uses it, and it passes values downstream, never the provider.
8 pages
Writing
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.
Writing
Programming to Exceptions, Part 1: Method Contracts and Failure
Method contracts let callers rely on completed work and let failures propagate. C# examples distinguish retrieval from search, validate domain entry points, and assign handling to its owner.
Writing
The Configuration Provider: Roles and Responsibilities
A Configuration Provider hides the source and returns validated, typed settings. Useful exceptions and composed settings providers keep configuration rules in one place.
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.