Subscriber

Definitions

1. A component that registers interest in a topic or event stream and receives messages asynchronously whenever a publisher emits matching events. In pub/sub systems like Kafka, Redis Pub/Sub, or RxJS Observables, subscribers are decoupled from producers and can be added or removed without changing the publisher.

   In plain English: A part of a system that signs up to automatically receive certain messages or updates whenever they're available.

   Example: "The email service is just a subscriber on the 'order.placed' topic — it doesn't know or care who published the event."

Related Terms

• Webhook
• Event
• Push Notification
• Message Bus
• Notify
• Producer
• Subscription
• Transactional Outbox