Please don't call any candidate if you have a bias in hiring, If you need a good candidate so please make your process like that first of all. And set up some proper technical interviews with someone who has ""working knowledge""" as there can be multiple approaches to any particular problem statement. so please make sure that the interviewer gets the technical things that the candidate is explaining. The last thing, the interviewer also should have enough diverse knowledge about the question he is asking before judging any good candidate. and also there is no right or wrong answer in Data Science for some problems.