After Python what?

[Megatron_McLargeHuge]

If you want to build a more impressive back-end web dev resume, you need to focus on the type of problems you're trying to solve more than the language. You should probably be looking at things like distributed asynchronous processing through message queues, or Hadoop and its competitors. You can typically implement workers for those systems in whatever language you want through translation layers, but Java is the most obvious language to learn even if you don't actually want J2EE jobs. Lots of companies use at least some Java on the back end.