Conclusions & Rankings
Complete rankings, detailed analysis, and decision guidelines for each architecture.
🏆 Final Rankings
| Criterion | 🥇 Gold | 🥈 Silver | 🥉 Bronze | ❌ Worst |
|---|---|---|---|---|
| Simplicity | A01 (6 files) | A02 (10) | A03 (14) | A04 (22) |
| Thin Controller | A02/A03/A04 (30-32) | — | — | A01 (184) |
| Thin Service | A04 (99+152) | A03 (123) | A02 (172) | A01 (184) |
| Testability | A04 (pure domain) | A03 (strategy) | A02 (service) | A01 (needs DB) |
| Extensibility | A04 (new Decorator) | A03 (new Strategy) | A02 (modify service) | A01 (modify controller) |
| Fragility | A04 (low) | A03 (medium) | A02 (medium-high) | A01 (high) |
Detailed Analysis
A01: Simplicity has exponential cost
Controller grew from 83 to 184 lines in a single method handling 13 responsibilities. Early booking discount amount is parsed from the discount_reason string (str_starts_with + explode) — a fragile hack.
Final Verdict: A01 is a trap. It seems cheap upfront but becomes exponentially expensive. Use only for short-lived prototypes or when you're absolutely certain complexity won't grow.
A02: God Service problem
Controller stays at 30 lines but all complexity moved to a 172-line 'God Service'. Repository Pattern decouples infrastructure but doesn't reduce algorithmic complexity.
Final Verdict: A02 is a solid middle ground. It's better than A01 for testability, but you're still stuck with a monolithic service layer. Good for teams transitioning to cleaner architecture.
A03: Strategy duplication
Phase04PricingStrategy duplicates all logic from BasicPricingStrategy just to add 3 methods. Good balance but needs refactoring to avoid strategy duplication per phase.
Final Verdict: A03 is the practical choice for many teams. It offers good testability, clear separation of concerns, and a structure that maps well to business concepts. Needs refactoring for phase-based evolution, but shows the value of strategy-based design.
A04: Horizontal scalability
Highest initial cost (22 files, 1139 lines) but scales horizontally: each new rule is a new Decorator file, not modified code. Builder + Decorator means Phase 05 barely touches existing code.
Final Verdict: A04 is for domains with frequent rule changes and teams comfortable with design patterns. It delivers on the Open/Closed Principle, but requires discipline and architectural maturity. The investment pays off in systems that evolve over years.
⚡ When to Use Each
Architecture selection based on your domain characteristics
Stable domain, no changing rules
→ A01 or A02
Product types with different formulas
→ A03
Pricing rules that change frequently
→ A04
💡 Key Insights
1. Cost Distribution Matters
A01 looks cheap initially (6 files) but concentrates all cost in one fragile point. A04 looks expensive (22 files) but distributes cost across independent units. The question is: where do you want the complexity to live?
2. Controllers Are Not the Bottleneck
A02, A03, and A04 all keep controllers thin. The real challenge is where business logic lives. Moving logic out of controllers to services doesn't reduce algorithmic complexity—it just relocates it.
3. Extensibility vs. Simplicity Is the Core Trade-off
A01 is simple but brittle. A04 is complex but extensible. A02 and A03 sit in the middle. Choose based on your domain's mutation rate and team's architectural maturity.
4. No Silver Bullet
Each architecture makes trade-offs. A01 trades long-term maintainability for speed. A04 trades initial complexity for long-term flexibility. The "best" architecture depends on your specific context.
👥 Recommendations by Team Context
Startup / MVP Phase
Use A01 or A02. Speed matters more than perfect architecture. Iterate quickly, refactor later.
Growing Product
Use A02 or A03. You need better testability and clearer code organization. Domain is getting complex.
Business Rule Variability
Use A03. Business rules vary by product type or context. You want to map code to business concepts.
Rapidly Evolving Rules
Use A04. Rules change frequently. You need zero-modification extensibility and strong design discipline.