From seeing the difficulties containerizing java application servers at my own workplace I would say the hard part is making the application server stateless wi

From seeing the difficulties containerizing java application servers at my own workplace I would say the hard part is making the application server stateless without sacrificing performance. Much of the older java (EE) ecosystem seems to assume a stateful application server that scales up, instead of a stateless one that scales out. Not that I think stateless is inherently superior, just that containerizing and scaling out sort of assumes moving state out of the application server and into redis, postgres, mongo, elastic, kafka, rabbitmq, …