Ask HN: How did you transition to a new programming language?

I have a decade of experience developing .NET applications and would happily continue, but there are simply not enough relevant open positions in my city. Unfortunately my job applications are dismissed out-of-hand before even reaching telephone call.

I've completed coursera courses in different languages and referenced them in cover letters, but with no feedback I assume this makes absolutely no difference.

How did you manage to even get an interview for a position using a language/environment you're not familiar with? Am I unlucky having to deal with the stigma of "uncool" .NET?