Microservice is a style of backend architecture where an application is split into small services — each owning a narrow job (payments, inventory, search) — that communicate through APIs or messages.

Compared with a monolith, each service can be deployed, scaled, and updated on its own. The tradeoff is complexity: more moving parts, network calls, and operational overhead. Splitting too early often slows teams down. Containers (Docker) and orchestration (Kubernetes) are common companions when you run many services.

A real-life example of a microservice

An online store keeps browsing and cart in one app, but runs payments and fraud checks as separate services. Black Friday load on the product catalog does not force the payment service to scale the same way. That separation is microservices — useful after the business outgrows a single tidy codebase.

For growth without premature complexity, see Scale Without Tears and the platform view in E-commerce Technical Pillars.