Messaging services such as Kafka or RabbitMQ can receive and sort a large number of messages while serving consumers at scale.
Spring Live: Developing fault-tolerant stream processing application with Kafka Streams and Kubernetes
An example of how to connect to, send, and receive messages from Kafka.
An example of how to connect to, send, and receive messages from RabbitMQ in several languages.
Build a basic Spring Boot application that uses JPA to access a database
Spring Cloud Stream Demo
Simple Event Driven Microservices with Spring Cloud Stream