Microservices vs Monolith: Making the Right Architecture Decision

✓ Simple deployment — one artifact
✓ Easy debugging — single process
✓ No network latency between components
✓ Simple transactions with database ACID
✓ Lower operational overhead
✓ Faster for teams under 10 developers

✓ Independent deployment per service
✓ Technology diversity per service
✓ Team autonomy — each team owns their service
✓ Fault isolation
✓ Independent scaling
✓ Organizational scaling for 50+ developers

app/Modules/
├── Users/
│   ├── Controllers/
│   ├── Models/
│   ├── Services/
│   └── Events/
├── Orders/
│   ├── Controllers/
│   └── ...
└── Payments/

Rules:
1. Modules communicate via events, not direct imports
2. Each module owns its database tables
3. No cross-module Eloquent relationships
4. Shared kernel only for truly shared code

Start with monolith if:
  → Team < 10 developers
  → Product in early stage
  → Simple domain

Consider microservices if:
  → Team > 30 developers across squads
  → Different components need independent scaling
  → Organization has DevOps maturity (CI/CD, K8s)

Monolith → Modular Monolith → Microservices

1. Identify bounded contexts
2. Extract into modules with clear interfaces
3. Replace direct calls with events
4. Extract high-traffic modules into services
5. Add API gateway and service discovery