I'm looking to start freelancing as a full-stack web developer, but before going out to find leads I want to get to know a particular tech stack very well. On the front-end side of things, I hear Angular is in very high demand, and React is also worth looking into. However, I'm more conflicted over choice of back-end tech. It seems like there's plenty of demand for node.js skills, but at the same time I know that lots of node.js devs are moving to Go because of node's debugging/performance shortcomings. And is there any demand for Go freelancers? The job market for Go seems much smaller.
Should I learn both as part of my freelance offerings?
As far as other back-end options go, I could maybe learn some Rails or some PHP CMS, but I'd much rather focus on JavaScript. I've done some Android/mobile work before and it isn't that interesting to me for now, even if there's money in it.