When you heard your friend wants to recruit someone who can master R, Rails and Swift at the same time....

What level of hell does one have to be damned to that they need to use all those in the same project?!

@nmunro my friend wants someone who can manage multiple projects. From what I know, he wants that person can be a data analyst, web developer and app developer

Good luck in his search then. I'm a web developer and I study other languages in my spare time. However my experience is I do not get on with R, MATLAB etc and the reciprocal is true.

That is to say the R and MATLAB programmers I know don't get on with other languages. It's anecdotal evidence sure, but it's a very specific skill set...