The java ecosystem is optimised for maturity, ruby the cutting edge. That is to say that the cutting edge java libraries are considerably more painful to use th

The java ecosystem is optimised for maturity, ruby the cutting edge. That is to say that the cutting edge java libraries are considerably more painful to use than the cutting edge ruby libraries. If you're the kind of team that gravitates towards newer libraries than ruby is going to be a better experience. If you prefer to plod along with good ol' faithful than java is the way to go.