Bounded Contexts and Service Boundaries

One of the most important decisions in microservices architecture is determining where one service should end and another should begin. Imagine you're designing an e-commerce platform with features such as product browsing, inventory management, order placement, payment processing, and shipping.

You could build everything inside a single service, or create a separate service for every feature. But neither approach automatically leads to a good architecture.

If services are too large, they become difficult to maintain and evolve independently. If they're too small, even simple operations may require communication across multiple services. The real challenge is identifying boundaries that make sense for the business.

This is where Bounded Contexts, a concept from Domain-Driven Design (DDD), become useful. Bounded contexts help us understand which business responsibilities belong together and where clear separation is needed.

In this chapter, we'll explore how bounded contexts relate to microservices, how to identify service boundaries, and how to avoid common decomposition mistakes.