Need Ruby and Node.js advice - NLP server.

[Steve]

I want to build an NLP server to interface with a WordPress plugin that I've already built.

I'm thinking about doing it in two parts: a JSON API server facing the plugins, built in Node.js (diet.js, hapi, not sure) for the quick I/O stuff, and a background job that sends the text to a separate server for analysis, built in Ruby (maybe Grape?) that wraps some standard and custom NLP libraries.

Any pointers or recommendations about setup, frameworks, hosting, that would be best for me?