Crossbar vs 2 backends?



I’m starting to dig deep on crossbar and its functionalities and was wondering how flexible crossbar can actually be.

If I have a project using django on the back end laying on top of a twisted server how does crossbar differs from javascripts frameworks like react or vue.js that need a nodejs backend to function?
I’m interested in adding realtime functionality that obviously frameworks like react can provide, but they need to be on a separate nodejs backend aside from the django backend which I don’t really found flexible trying to set up just to make a framework to function.
Therefore I came with the idea why not to use crossbar, since although I’m not really informed deeply yet on its funcionality I feel like it can be useful and much flexible than using two backends.
So, are there any differences? Can crossbar serve for my purpose and thus avoid javascript frameworks that depend on another backend?

As far as I’m concerned, real-time frameworks are build based on an architecture of routing and event-driven programming.