When to Actually Use Microservices

The Microservices Trap

Microservices are sexy. They're also expensive. Every new service is a new deployment pipeline, a new place for bugs to hide, and a new boundary across which things can fail.

So when should you actually use them?

Start With a Monolith (Really)

For most products, a well-structured monolith is the right choice for years. You can: - Deploy one thing - Debug in one place - Refactor across "modules" without network boundaries - Move fast with a small team

The key is structure: clear modules, explicit dependencies, and the discipline to not turn it into a big ball of mud.

When to Consider Splitting

Split out a service when you have a concrete reason, not a vague "we might scale someday." Good reasons include: - Different scaling needs: One part of the system needs to scale independently (e.g. image processing vs API). - Different teams: Multiple teams need to own and deploy their part without stepping on each other. - Different failure domains: You want one component to fail without taking down the rest (e.g. a background job processor). - Different tech or runtime: One piece genuinely benefits from a different language, framework, or resource profile.

What I've Seen Work

The best migrations from monolith to services I've seen: 1. Extract one high-value, well-bounded capability first (e.g. "notifications" or "billing"). 2. Run it in production alongside the monolith. Learn. Iterate. 3. Extract the next one only when there's a clear need.

The worst: "We're going microservices" as a big-bang rewrite. Don't.

The Bottom Line

Use a monolith until it hurts. Then extract services for specific, well-understood reasons. You'll save yourself a lot of distributed systems pain — and ship faster.