When a microservice directly call another service, they become dependent on each other, and need to be tested and deployed together. Meaning you are actually losing the “Micro” in microservices. Equally relevant for rest , soap, graphql. They will be coupled both in data model and in time Should put messages on a queue instead. See this for instance https://www.linkedin.com/pulse/common-microservice-anti-patterns-how-avoid-them-chase-o-neill/