AWS SNS

Amazon Simple Notification Service (SNS) is a fully managed pub/sub messaging service. Publishers send messages to topics, and subscribers receive them via SQS, Lambda, HTTP/S, email, SMS, or mobile push. It's the glue for fan-out architectures.

Core Concepts

• Topic — a logical channel for publishing messages
• Subscription — an endpoint subscribed to a topic (SQS, Lambda, HTTP, email, SMS)
• Message filtering — JSON policy to route only matching messages to a subscriber
• Fan-out — one message published, delivered to all subscribers simultaneously
• FIFO Topic — ordered, deduplicated delivery (pairs with FIFO SQS queues)

Topics

# Create a standard topic
aws sns create-topic --name order-events