If a candidate is active on Github I like to check their profile to get a sense of what they are interested in and what their code looks like.
If a candidate is not active I don't hold it against them, I just ask different questions.
I do the same. Since I'm usually asked to do the tech part of the interview process, I think it is a nice and easy way to extend the picture of the candidate. But it is not a must-have.
I also like it, because I'm curious and love to get more inspiration. I try to keep this out from the evaluation though. I say "try", because once looked at the profile we're unconsciously biased anyway. But I hope I still gave every candidate an equal chance, no matter if and how much they have shown publicly.
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