Tell me about synchronous and asynchronous interactions — how do you understand this in your own words? Can you give an example from practice?

Synchronous interactions are when one process or system waits for the completion of another system's operation before continuing. For example, when calling an API, the client waits for the server's response before proceeding.

Asynchronous interactions allow the initiator not to wait for the operation to complete and to continue working. The result of the operation arrives later, for example, via callback, event, or message queue.

A practical example: in a order processing system, a synchronous call may be used to check the availability of a product — the client waits for confirmation. Asynchronously, sending notifications to the client can be processed — the system puts the task in a queue and continues working, and the notification will be sent later.