Well, the client side is compiled by eclipse automatically and the client can be configured for development so that many classes aren't cached so you can test cosmetic changes without a restart.

On the server side however if you add new components, services or introduce new fields in existing entities you have to restart the JBoss and build the changed component.

It is enterprise, I'm working on the market-leading MES (Manufacturing Execution System) solution for the pharma- and biotech area. Our internal framework alone consists of around 3.700 classes.