Is it possible to be an expert at multiple programming languages and platforms (e.g. C#/.NET, **Objective-C/Cocoa, Java/Spring…Hibernate) assuming you spend 5-10 years developing software with it.
Or is it always going to lead to being good at one thing and mediocre at the rest?
To put it in different words: To focus or not to focus in one development language/platform.
PS: Please don’t bring up Jon Skeet as an example. We all know he doesn’t have to even learn programming languages; programming languages learn from him. Our assumption is an average developer.
A lot of .Net Developers came from Java or C++ background. So, yes I have seen several developers work on different platforms. I have worked on C, C++, Perl, AWK, JBOSS/SEAM, LAMP, and .NET stacks. There are people who know more languages than myself. More importantly you should work on mid-large projects to fully get the experience. The fundamentals are the same. Every language or stack has the same challenges when it comes to concurrency, exception handling, etc,…