Microservices architecture: when to use it and when not to
Microservices have become the trendy architecture. But adopting microservices without the right technical maturity can create more problems than it solves.
What are microservices really?
A microservices architecture breaks an application into small, independent, separately deployable services. Each service has its own database, its own deployment cycle, and communicates with others through APIs or messaging.
When you SHOULD use microservices
Your team has more than 15–20 developers: Microservices let independent teams work in parallel without stepping on each other. If your team is small, coordination between services will cost more than the benefit.
Different parts of the system scale differently: If your payments module needs to handle 10x more traffic than your reporting module, microservices let you scale each part independently.
You need frequent, independent deploys: If a change to the notifications module shouldn't require redeploying the whole system, microservices are the answer.
You use multiple technologies: If your data processing is better in Python and your API in Node.js, microservices let you pick the best tool for each job.
When you should NOT use microservices
You're starting a new product: You don't yet know the domain's boundaries. A modular monolith lets you iterate quickly and discover the natural service boundaries.
Your team is fewer than 5 people: The operational complexity of microservices (networking, service discovery, distributed tracing, failure handling) will consume a small team's capacity.
You don't have a mature DevOps culture: Microservices require automated CI/CD, distributed monitoring, centralized configuration management, and secrets handling. Without these, it's chaos.
The alternative: a modular monolith
A well-structured monolith with clear modules, defined interfaces, and separation of concerns gives you 80% of the benefits of microservices with 20% of the complexity.
The structure is simple:
- Each module has its own folder with controllers, services, and repositories
- Modules communicate through defined interfaces, never accessing another module's database directly
- When a module grows enough, extracting it into a microservice is a surgical operation, not a rewrite
Our recommendation
Start with a modular monolith. Measure. Identify the real bottlenecks. Extract microservices only where the data proves it's necessary. This pragmatic approach has proven more successful than designing microservices from day one.