A Modular Monolith That Doesn't Hurt

Structure that survives

app/
├── Modules/
│   ├── Billing/
│   ├── Reporting/
│   └── Identity/
├── Services/
└── Support/

Rules I follow

• Modules never query each other's tables directly.
• Cross-module communication goes through service classes or events.
• Queues for anything slow: exports, emails, audit writes.

Why it works

You get 80% of microservices' clarity with 20% of the operational cost. When a module truly needs independence, the extraction is mechanical — not a rewrite.