What else was in the microservice besides asynchronous processing?

In addition to asynchronous processing, a microservice typically includes the following components and aspects:

• API for interaction — REST or gRPC interfaces for communication with other services or clients.
• Logging and monitoring — collection of metrics and logs to track the state and performance.
• Error handling and retries — mechanisms for fault tolerance.
• Data storage — integration with databases or caches.
• Authentication and authorization — access rights verification.
• Configuration and state management — ability to change parameters without restart.
• Documentation and tests — for support and development.

Depending on the task, a microservice may also include other functional blocks, such as message queues, caching, load balancing.