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hamza zeryouh
hamza zeryouh

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Why You Should Start with a Modular Monolith Before Jumping into Microservices

In the era of distributed systems, microservices are often hailed as the golden standard for scalable architecture. Companies like Netflix and Amazon made them famous, leading many startups and teams to believe they need microservices from day one. But is it really the best path forward?

Not necessarily.

For most early-stage products and growing teams, starting with a Modular Monolith is a smarter, faster, and more sustainable decision. Let’s dive into what it means and why it’s a better starting point.

What is a Modular Monolith?

A modular monolith is a single deployable application structured internally into well-separated modules. Each module represents a feature or a domain (e.g., User, Orders, Payments) and communicates with others via clean interfaces.

It offers the same internal boundaries and discipline you’d aim for in a microservices architecture—without the overhead of distributed systems.

Why Start with a Modular Monolith?

1. Simplicity in Deployment

Microservices require orchestration (Docker, Kubernetes), service discovery, load balancing, and more. In contrast, a modular monolith is just one app, one database, one deploy—easy to host and debug.

Ideal for MVPs and fast iteration cycles.

2. Faster Development

You don’t need to spin up multiple services or manage inter-service communication. All modules live in the same codebase and memory space, making refactoring and feature development much faster.

3. Easier Debugging and Testing

Monoliths don’t suffer from network latency or distributed tracing problems. With logs and stack traces in one place, debugging becomes drastically easier.

4. Lower Infrastructure Costs

Microservices come with cost: each service might need its own container, CI/CD pipeline, monitoring tools, and hosting. A modular monolith is cost-effective, especially for small teams and startups.

5. Natural Path to Microservices (When Needed)

If your system grows and you hit scaling or team autonomy limits, you can extract a well-designed module into its own microservice.

A modular monolith lays the groundwork for microservices—without the premature complexity.

Best Practices for Modular Monoliths

  • Use Domain-Driven Design (DDD) to define module boundaries.
  • Encapsulate logic: no direct access to internal state of other modules.
  • Use dependency injection and interfaces to enforce loose coupling.
  • Consider modular folder structure, namespaces, and clear API boundaries.
  • Include internal contracts but expose only what’s necessary.

Final Thoughts

Don’t be fooled by the hype. Microservices are not a silver bullet—they’re a scaling strategy, not a starting point.

Start small. Stay focused. Build a solid foundation with a modular monolith—and evolve to microservices only when your system and team truly require it.

Start smart. Scale later.

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