How do you implement service composition in microservices-based applications?

Service composition is the process in which multiple independent services collaborate to complete business functions in a microservices architecture. Its importance lies in enhancing system modularity, improving maintainability and scalability, with application scenarios including workflows such as e-commerce order processing and user identity authentication.

Core components include API gateways for coordinating requests, inter-service communication mechanisms such as RESTful API calls or message queues, and event-driven design characteristics such as loose coupling and service discovery. In practical applications, API gateways aggregate backend responses to simplify client calls; the impact is to promote elastic scaling and simplify distributed transaction management.

Implementation steps: Define service interface specifications; implement calls using HTTP APIs or event buses; handle data aggregation and error handling. A typical scenario is that user login requires an authentication service to combine user data services. Business values include improving response efficiency, reducing coupling, and supporting rapid iteration and innovation.