Fan-out is a messaging pattern; ‘fanned out’ to multiple

destination in parallel.

▪ Each of destinations can work and process this messages in

parallel.

▪ Publisher/subscriber model to define a topic which is

logical access point to enabling message communication with

asynchronously.

▪ Publisher sends the message to the topic, message is

immediately fanned out to all subscribers of this topic.

▪ Each service can operate and scale independently and

individually that completely decoupled and asnycronously.

▪ The publisher and the subscribers don’t need to know who is

publishing / consuming this message that is broadcasting.

▪ Deliver the same message to multiple receivers is to use the

Fanout Publish/Subscribe Messaging Pattern.

https://medium.com/aws-lambda-serverless-developer-guide-with-hands/publish-subscribe-fan-out-pattern-in-serverless-architectures-using-sns-sqs-and-lambda-bccaa3abac9e