Backend
What is Message Queue?
An intermediary buffer that stores messages from producers until consumers process them, decoupling services and absorbing traffic spikes.
Definition
A message queue lets a producer hand off work as a message and move on, while one or more consumers pull messages and process them at their own pace. This decouples services in time: if a consumer is down or slow, messages wait in the queue instead of being lost. RabbitMQ, Amazon SQS, and ActiveMQ are classic brokers; Kafka serves a similar role with a persistent log model. Queues underpin background jobs, order processing, and retry pipelines, and typically offer at-least-once delivery, so consumers should be idempotent.