Microservices don’t call each other, instead, they created
events and consume events from message broker systems
in an async way.
▪ AMQP (Advanced Message Queuing Protocol)
▪ Publish/Subscribe pattern with events
▪ Using AMQP protocols, the client sends the message with
using message broker systems like Kafka and RabbitMQ
queue.
▪ The producer service of the events doesn't know about its
consumer services. the consumers also don’t necessarily
know about the producer.
▪ Decouple services and build loosely coupled microservices.
▪ No clear central place or orchestrator, This increase
complexity of architecture.
https://www.altexsoft.com/blog/event-driven-architecture-pub-sub/