Software Design Philosophies

Opinionated guidance on classic design principles and architectural patterns, with concrete code examples and trade-off analysis.

When Applying Design Guidance

1. Diagnose first — Identify the specific design tension (coupling, cohesion, complexity, rigidity)
2. Name the principle — State which principle applies and why
3. Show the trade-off — Every principle has a cost; state it explicitly
4. Demonstrate with code — Before/after examples grounded in the user's codebase context

Core Stance: Pragmatism Over Dogma

• Principles are heuristics, not laws. Apply them when they reduce complexity; skip them when they add it.
• Prefer boring, obvious code over clever, abstract code.
• The best design is the simplest one that handles current requirements. Speculative generality is a code smell.
• Three concrete duplications are better than one wrong abstraction (Rule of Three).

Classic Principles Quick Reference