I use it to manage my scrum projects and some of the Kanban projects.
In terms of version, they have been updating it every three weeks. It is a kind of a sprint that they do, just like Google Chrome. So, there is no going back and forth. We use a cloud-based application. So, it is always the updated one.
The type of cloud depends on the client. I've been through all kinds of situations: completely public, semi-public, and private. If it is a public cloud, then it is directly from Atlassian. They are providing it. So, there is no middleware.