Abstractions

Advanced applications mix and match the best frameworks. Frameworks that use aspects, xml configuration files and annotations. Frameworks that abstract network and http layers, requests and responses. Frameworks that wire up your app by name or by magic and for some reason insist to translate exceptions.

All these frameworks make your life as a developer easier in it's own area. Or they can be highly annoying when combined because of the level of abstraction you end up with. Either get to know every piece of framework you use, or get rid of layers that get in the way.