When and why should asynchronous interaction be used in systems?

Asynchronous interaction in systems is used to improve performance, scalability, and responsiveness of applications. Main reasons and cases:

• Handling long operations without blocking — e.g., database queries, network calls, I/O operations. Asynchrony allows the main thread to continue working.

• Increasing scalability — asynchronous systems can handle more requests simultaneously because they do not wait for operations to complete.

• Improving user experience — interface remains responsive while background tasks are running.

• Implementing event-driven architecture — components exchange messages and respond to events without direct waiting.

• Integration with external services — asynchronous calls allow efficient work with remote APIs.

Example: a web server that processes requests asynchronously can serve thousands of clients simultaneously without creating a separate thread for each request.