Modular Monolith vs Microservice — Why I Start with the Monolith

The Short Version

I default to a modular monolith first.

Microservices are an expansion strategy, not a starting strategy.

Why Teams Reach for Microservices Too Early

Microservices sound attractive:

• they look scalable
• they feel modern
• they resemble what larger companies use

But early-stage products usually have different problems:

• small teams
• unstable domain boundaries
• rapidly changing features
• limited operational bandwidth

In that environment, microservices often import complexity before they solve a real scaling problem.

The Real Cost of Microservices

Splitting services does not only split code. It multiplies operations:

• inter-service communication
• multiple deployment pipelines
• more secrets and environment management
• distributed logs and failures
• API contract coordination

That is often too much overhead for an early product.

Why I Prefer a Modular Monolith First

A modular monolith keeps:

• one deployment unit
• one runtime boundary
• simpler operational reasoning

while still enforcing strong internal module boundaries.

That gives me a better place to learn where real service boundaries should eventually exist.

My Rule

Start with a modular monolith.
Keep module boundaries explicit.
Split only when the need becomes operationally and product-wise obvious.