Message Queue

A message queue is an asynchronous communication mechanism that enables services to exchange messages by having producers write messages to a queue and consumers read and process them independently. Message queues decouple services, improve resilience (messages persist even if consumer is down), and enable load leveling by buffering bursts of messages. The publish-subscribe pattern (pub/sub) extends this to broadcast messages to multiple consumers. Examples include RabbitMQ, Apache Kafka, AWS SQS, and Azure Service Bus.