Introduction to event-based programming

Event-driven programming is a paradigm where entities communicate indirectly by sending messages to one another through an intermediary, typically stored in a queue before being handled by the consumers. This approach completely decouples the producer from the consumer and allows for multiple producers and consumers to collaborate on processing incoming requests. It also simplifies retries and maintaining event history while making it easier to scale large systems. Key components of an event-driven system include events, producers, consumers, and message queues. Event-based programming opens the door to several useful patterns such as single producer/single consumer, single producer/multiple consumers, dead letter queue (DLQ), time to live (TTL), and asynchronous request-response with events.