'I know that it's rare to find a true indication of someones ability from just their github contributions but for example, it can help me discern whether a ruby candidate adheres to ruby best practices or not.'
The problem with this is that you can't really make a logical decision when the code (on Github/bitbucket) is removed from its context. Maybe none of the code follows best practice, but there is a compelling reason why this is so. If your decision on whether to pursue a candidate or not does not include a discussion with the candidate about their available code, you are missing an integral piece of the puzzle.
If your decision on whether to pursue a candidate or not does not include a discussion with the candidate about their available code, you are missing an integral piece of the puzzle.
You are absolutely right. I can honestly only ever think of one circumstance where I dismissed someone based exclusively on what I saw in their github repo. I felt guilty so I phoned them a week later to discuss my thoughts and it turns out my suspicions were correct but that was categorically an edge case.
The problem with this is that you can't really make a logical decision when the code (on Github/bitbucket) is removed from its context. Maybe none of the code follows best practice, but there is a compelling reason why this is so. If your decision on whether to pursue a candidate or not does not include a discussion with the candidate about their available code, you are missing an integral piece of the puzzle.