When is it preferable to directly interact between microservices, and in which cases is it better to use other approaches?

Direct interaction between microservices (e.g., via REST API or gRPC) is preferred when:

• Low latency and high data exchange speed are required.
• Services are closely related and frequently exchange information.
• The architecture is simple and the number of microservices is small.

However, in the following cases, it is better to use other approaches, such as asynchronous interaction through message queues (RabbitMQ, Kafka):

• When ensuring system resilience and fault tolerance.
• To unload services and increase scalability.
• If interaction between services does not require an immediate response.
• To implement event-driven architecture.

Thus, the choice depends on the requirements for system performance, reliability, and complexity.