What is the production-readiness of sails.js and meteor.js, and how to they compare to Django?

I am thinking of using either one of them in building our startup which is like a job portal with validation,verification and includes special features for freelancing and all.

Is meteor or sails good for using as a backend or should we go with more robust backend like Django? Will using javascript on our backend provide the ability to scale in the future moreso than Django/python?

I would really like some opinions in this matter to get to a decision.