What is the difference between synchronous and asynchronous integration?

Synchronous integration implies that the system sending the request waits for a response from another system before continuing its work. It's similar to a phone call: you speak and wait for an immediate response.

Asynchronous integration means that the sender sends a message and does not wait for an immediate response, continuing its work. The response may arrive later or not at all. An example is sending an email or a message to a queue.

Key differences:

• In synchronous integration, the delay in response affects the sender's operation.
• In asynchronous integration, interaction occurs through an intermediary (for example, a message queue), which increases robustness and scalability but complicates error handling and data consistency.

Example: REST API is usually synchronous, while message-based systems (RabbitMQ, Kafka) are asynchronous.