What is Microservice?

What is a Microservice?

Microservice architecture splits a single application into small services organized around business capabilities. User management, payments, invoicing, notifications, and reporting can each become separate services.

Each microservice has its own codebase, release process, and often its own database. Services communicate through HTTP APIs, message queues, or event streams instead of sharing one large internal code path.

How Microservices Are Designed

• Service boundary: It should follow a business capability, not just a technical layer.
• Independent deployment: A new version of one service should be releasable without redeploying the whole system.
• Data ownership: Each service should be the source of truth for its own data; shared database coupling should be limited.
• Observability: Logs, metrics, and traces are essential for debugging distributed failures.
• Resilience: Timeouts, retries, and circuit breakers are needed because network calls can fail.

Business Use

Microservices are useful when multiple teams work on the same product, some business areas need different scaling behavior, or modules must evolve independently. In a marketplace platform, search, cart, payment, and shipping services may each scale differently.

The architecture is not automatically simpler. It adds network latency, distributed transaction concerns, version compatibility, and monitoring overhead. In many products, a well-structured modular monolith is a better starting point before splitting into services.

Microservice systems often use an API Gateway to manage external traffic and REST API conventions for predictable service communication.