How did the interaction between individual microservices occur in the system?

Interaction between microservices usually occurs through well-defined APIs, most often REST or gRPC. Each microservice provides a set of endpoints that other services can access to obtain data or perform operations. Message brokers, such as Kafka or RabbitMQ, can be used for message exchange, enabling asynchronous interaction and increasing system resilience. It is important that the contracts between services are well documented and API versions are controlled to avoid failures during updates.