Snarky. Glad you ended your comment with a constructive "learn Javascript".

Great advice. Except for JavaScript on the backend. That's horrible advice. ;)

Yeah but the more advanced fields of physics like quantum mechanics are way harder than anything in chemistry. It's actually a good analogy though, they are pretty similar in difficulty at the beginner through intermediate levels, but once you get into the advanced stuff they begin to differentiate.

A lot of chemistry is quantum mechanics. What is a "less advanced" field of physics anyway?

An example of a less advanced field of Physics than quantum mechanics would be Newtonian mechanics, such as is taught to college freshmen and sophomores. At least it seemed a lot easier to me.

There are people doing very advanced and difficult things in classical mechanics, even if they aren't the problems or topics that show up in a freshman physics course. There are also trivially easy quantum mechanics courses out there, so even if you are going to rank fields of physics by how "advanced" they are, I don't think going off the order they're taught to undergrads is reasonable.

That isn't a field of physics that's a high school textbook.

> Yeah but the more advanced fields of physics like quantum mechanics are way harder than anything in chemistry.

That's a very loaded statement. If this were a forum for the physical sciences (as opposed to computer science), that would probably be analogous to saying "Android is easier to develop for than iOS" or "Java is easier than C#" (both of which would easily start flamewars on HackerNews)

Yeah, still... it's true.

Please don't write backend in JavaScript. It's an ugly hack language full of pitfalls that we're stuck with for now on web pages; why put it on the backend where uptime and reliability are even more important? You need a slew of extensions to make it predictable and debuggable enough in that situation. I have yet to come across a situation where I really needed to share a library between my web page and server application, but I have in the client and server of a non-web game, so there are probably reasonable scenarios where it's useful, but from what I've heard getting a JS library to the point of portability between both webpages and node/other JS backends is more trouble than it's worth. PHP is even more of an ugly hack language filled with pitfalls. I've had a much better time writing backend in either .NET or python. Python's looseness still made it harder to deal with for complex situations but it's decent. If you like the idea of .NET on the backend but don't want to or can't have mono/.NET there's JSP which also is probably a good idea.

Web apps have been tilting more heavily toward the frontend (using a backend as an API/data layer), and I don't see that slowing down any time soon, so the frontend is the way to go, IMO.

If we're targeting the frontend and assuming OP's friend has limited experience programming, there's a benefit to learning the same (flawed) language in both the back and frontend, instead of learning two languages. Even if that one language is flawed.

I've shared code between Node and the browser using Browserify [0], and it's pretty easy. Page size can take a hit if you use modules that are meant for the backend and have large dependency graphs, but even then it could be worth it.

[0]: http://browserify.org/

True, and also front-end doesn't have to be based on legacy tech (HTML/JS/CSS). In this mobile-first world, native is a good option. Xamarin Forms is worth looking at.