The video tutorial discusses the application of fan out, publish, and subscribe messaging patterns in microservice architecture. It covers the design toolbox, functional and non-functional requirements, and both synchronous and asynchronous communication patterns. The tutorial explains the implementation of a publish-subscribe module to enable asynchronous communication between microservices, ensuring loose coupling and independent scaling. The final architecture includes key microservices like catalog, shopping cart, discount, and ordering, with a focus on decoupled message communication.

Describe the role of a message broker in the microservices architecture.

How does the publisher-subscriber model ensure loose coupling between services?