From Monolith to Microservices: When and How to Make the Transition

The Microservices Hype Cycle

Microservices are often presented as the default architecture for modern applications. But the truth is more nuanced: many successful companies run monoliths at scale, and premature decomposition creates more problems than it solves.

When to Stay Monolithic

A well-structured monolith is perfectly fine when:

• Your team is small (under 10 engineers)
• Your domain is well-understood and relatively stable
• You're optimizing for development speed over operational complexity
• Your deployment frequency doesn't require independent service releases

Signs You Need Microservices

Consider decomposition when:

• Team scaling friction — Multiple teams stepping on each other in the same codebase.
• Deployment coupling — A change in one area requires deploying the entire application.
• Scaling constraints — Different parts of your app have vastly different resource needs.
• Technology diversity — Some problems are better solved with different tech stacks.

The Strangler Fig Pattern

The safest migration strategy is the Strangler Fig pattern: gradually extract functionality into services while keeping the monolith running. Route traffic to new services incrementally, and only decommission monolith code when the service is proven stable.

Key Lessons

Start with a modular monolith. Define clear boundaries between modules. When you eventually need to extract a service, the boundaries are already there. Don't distribute what doesn't need to be distributed.