Starting with a monolith is often the right choice. After building both monoliths and microservices, here’s when monolith-first makes sense.

When to Start with Monolith

Good Reasons

  • Small team - Limited resources
  • Uncertain requirements - Evolving domain
  • Fast iteration - Rapid development
  • Simple domain - Straightforward logic

Benefits

  • Faster development - Less overhead
  • Easier debugging - Single codebase
  • Simpler deployment - One service
  • Lower complexity - Fewer moving parts

Monolith Structure

Modular Monolith

// Organize by domain
src/
├── users/
│   ├── domain/
│   ├── application/
│   └── infrastructure/
├── orders/
│   ├── domain/
│   ├── application/
│   └── infrastructure/
└── shared/

Migration Strategy

When to Split

  • Team size - Multiple teams
  • Scale - Performance issues
  • Domain clarity - Clear boundaries
  • Deployment - Independent releases

Strangler Fig

Gradually extract services:
1. Extract one domain
2. Route traffic
3. Migrate data
4. Deprecate old code

Best Practices

  1. Start simple - Monolith first
  2. Keep modular - Clear boundaries
  3. Monitor - Track metrics
  4. Plan migration - When needed
  5. Don’t over-engineer - YAGNI principle
  6. Refactor regularly - Keep clean
  7. Document - Clear structure
  8. Evolve - Adapt as needed

Conclusion

Monolith-first enables:

  • Faster development
  • Simpler architecture
  • Easier maintenance
  • Lower complexity

Start with monolith, evolve to microservices when needed. The strategy shown here balances speed and complexity.

Monolith-first strategy from October 2023, covering when to start with monolith and migration strategies.