What is "messaging"? Is it useable only on premise or even in the cloud? During this day/session, we will have a brief introduction around "messaging" with related patterns, interoperability problems and the main components like brokers and routers which make it possible. After that, we'll see how it's possible to develop a "message as a service" platform running into the cloud addressing all configuration and scalability problems. This journey will be driven by the EnMasse project, an open source cloud messaging platform able to run on Kubernetes and OpenShift.