.NET Architecture & System Design Interview Question #113

What is synchronous communication between services?

Microservices, API Gateway, Service Communication & Event-Driven Architecture Mid-Level Intermediate

Quick Interview Answer

Synchronous communication requires the caller to wait for the downstream service to respond, commonly through HTTP or gRPC.

Detailed Explanation

Synchronous communication requires the caller to wait for the downstream service to respond, commonly through HTTP or gRPC.

It is appropriate when the caller needs an immediate result, but it creates runtime dependency between services. Long synchronous chains increase latency and the chance that one downstream failure affects the entire request.

Code Example

Client -> Service A -> Service B -> Service C
           waits       waits

Total latency includes downstream calls.