I've heard much talk about your Github profile being your CV and companies supposedly using Github to find employees. But I've never heard of anyone actually being hired primarily due to their OSS contributions. And then I see something like this, where potential employers still expect the candidate to complete pointless, unpaid assignments, despite the candidate's publicly available OSS contributions being in the relevant problem domain.
The refusal of employers to use OSS contributions as a means of gaging competence and the continued insistence on candidates, however impressive their publicly available OSS portfolio, answering CS trivia questions and completing unpaid assignments suggests that if they really value OSS contributions at all, it's probably only because it demonstrates enthusiasm, and enthusiastic employees are easier to manipulate and abuse. That's it. A Github profile will never shorten an interview or spare your from having to write a function to reverse a linked list in-place.
Maybe I am being too cynical. Has this actually worked for any of you, whether in getting hired or in hiring someone?