Which of the big 3 languages (Java, C++, C#) do you think gives the greatest overall prospects for a technical career in finance? Depends upon your risk/return utility (this is finance forum, if you aren't thinking in those terms about your career in those terms, you aren't ready to have one).C# is the safe short to mid term option, supply/demand is good for the developers who know it and appears to be getting better.Java has more jobs than C# or C++, I have said publicly and often that this will end really badly because supply is increasing faster than demand.But to get a job in a bank today the best skill to have is either C# or Java, not C++That's because if you put C++ on your CV, they will expect a higher level of skill than for a C# or Java programmer, there is a critical mass of C++ you need else you're more dangerous than useful. So C++ can get you a better job, but if you don't make the cut you fall between two stools.Of course the next variable is what job...Some HFT is done in Java but frankly not much and even where the people running the team ask for Java (rarely) they ask for C++ to prove you're "deep" and because they realise that hard programming will be necessary when Java gets pushed far beyond what it is designed to do.Some semi-automatic trading is done in C#, for various reasons that correlates with hedge funds, but the same interaction with C++ is to be found, more so since Windows is in it's heart a C/C++ O/S, actually any O/S you've ever used it written mostly in C, with C++ and C on top of the base. After C, the next most common language is assembler, though VHDL is lurking in the shadows. Java & C# are used for prototyping some strategies and for code that connects the Formula 1 HFT systems to the Range Rover general IT in the bankPrototyping however is more the real of Matlab, R, Python and Mathematica, and since you're asking about "technical" roles that's not so relevant to you.Of course a big risk term is that HFT is not politically popular which may affect your career prospects if it is regulated out of profitability and any given trading desk of any kind may at any time explode and die. Although I talk as if I know all the answers (I'm a quant headhunter), actually the most important terms are entirely unknown to me.Are you a much better programmer than the average, I don't mean top quartile, but at least top decile ?Do you know how operating systems work ?I don't much care if anyone taught you, but if your mindset hasn't already caused you to try and find out at a technical level then you probably won't prosper in this line of work.How many questionable things have you ever done to computers ?Hacking may be perjorative term, but how many times have you made a system do things it was not not designed to do ?The smaller that number, the less your chances.How are your maths ?