I'm mostly happy working in my c# job, but when I browse job listings (particularly startups), it seems that the positions I personally find to be most interesting require lots of experience with a linux stack, c++, and python. I coded in c++ for a few years (it was my first programming language), but that was nearly a decade ago. The job postings I see all "require" years of experience.
More important than just the job, I actually rather enjoy coding in c++ and python. I like how low level c++ feels and I love how python lets me get lots done. But beyond tinkering, I know I don't have a professional level of proficiency yet.
I also fear that my Microsoft-oriented background will be, for these sorts of jobs, a black mark on my resume. Should I play-down that experience at the risk of looking like I haven't accomplished much over the past years?
I don't mind the current economy too much, since I expect such a transition will take at least a year or two. How can I build the skills and more importantly, once I have the skills, how can I show potential employers that I am qualified?
Are there any fields that need programmers with a combined c#/c++/scripting language skill set?
Are there any fields where a c# background would be the natural pool of experience to draw from for a non-microsoft technology?