Comment by playing_colours

Did you have any experience doing web development with Scala? I am now choosing stack for my new project and considered Scala/Play as an option. There are some problems both with Play2 framework atm(no Wax deployment support, long rebuilding after small changes, work with actions is confusing) and the language of Scala (complexity, version migration, SBT etc.) The situation is promised to get better in future but most need their work done now. If you are choosing bleeding edge, new shiny thing be ready to face additional problems which can slow your development. If you prefer just to get things done you'd review your Python code, find and fix bottlenecks. Maybe you can combine techs choosing what is appropriate for some work - say Python for web interface with critical parts in Java/Scala.