I'm currently a .net developer working mostly with closed source tech. I'm trying to transition into open source development but finding jobs is hard because x years requirement, although i'm i think it will be simple to transition into other languages.<p>Any advice ?
Sounds like you have experience working in a development environment, so the transition should not be difficult (coding is part of it. Other things such as testing,refactoring,good design take up more importance as well). Small projects would be great just to get yourself familiar with the syntax of those languages, but if you are comfortable with the .NET, a transition to Python/JavaScript should be relatively easy.<p>I would say this though. You can leverage .NET with open source via .NET Core.
I would start a small hobby project in whatever language and platform you'd like to work with, pick something you enjoy so that you keep building it for a while. That's real experience that will expose you to many issues you wouldn't have known about otherwise, and will give you lots of platform-specific things to talk about in addition to your previous experience.