An anonymous reader writes: Hi, I've been a software engineer for about 15 years most of which I spent working on embedded systems (well they are small custom systems running Linux so far as the embedded part) developing in C. However, web and mobile technologies seem to be taking the world over, and while I acknowledge that C isn't going away anytime soon, many job offers (at least those that seem interesting and in small companies) are asking for knowledge on these new technologies (web/mobile), which incidentally I am interested in anyway.
The thing is that there are so many of those, Objective-C (for iOS) and Java (for Android), Javascript/CSS (for the web), Qt for cross-platform, etc. for the "front-end" part (not counting UX -ie: GUI design-), and then there's the "back-end" part, which has MySQL/NoSQL, Node.js, Ruby, and many seem equivalent like PHP/Python; and then there's a bunch of new languages and programming paradigms (functional programming, etc.). So it is very hard to pick (at least without prior knowledge) which ones are worth investing in for somebody with a limited amount of time, yet there seem to be a growing bunch of under 25 wiz kids that seem to know every one of these new technologies and get to change jobs like changing shoes!
Where would you suggest to start with to somebody that wants to learn a few of these kind of things to be employable again? How long do you think it should be devoted to learning this? Like, what would be the smallest set of "new technologies" that one should know to be employable these days?