Just learnt Vue js. Now I need to learn a backend framework. Django or Node js? Which one should I learn?

Depends. Do you prefer the syntax of JS or python?

Go with node if you like js

The Laravel crowd seems to be in love with Vue, so maybe that goes both ways?

Do node.js, the reason is simple same tools and same language as your frontend.

@Flygger If you want to learn your first backend thing, don't start with Laravel. It's convenient for certain projects, but teaches you so many wrong habits. Same actually goes for Rails and Django... You could learn them, and they're commercially useful, but you are at risk of getting confused by the magic and making wrong assumptions about how the clockwork ticks.

I'd pick NodeJS first if you want to be productive as soon as possible, because you already know JS.

If you want to learn backend, take PHP or Python or Go or Java, and try to set up your own MVC/MVVM framework. From scratch. Not because you must use your own reinvented wheel, but because it makes you understand how wheels work.

I think Node and Go are actually great starting places for that, because they offer simple integrated starting points to build on top of.

@bittersweet i think i did your tl;dr :P

I already know flask but I heard it's not widely used compared with node or Django.

Well python flask would be easier to grasp than django. Specially since apis come natural to flask (django too, but flask is more minimal)

Just an fyi we do have some badass front ent gems in Rails land if you are interested in the framework. Rails is pretty nice and simple. But if you like Python better you cannot go wrong with flask or django. Also, node + express (or koa) and vue is pretty awesome.