I&#x27;ve used Codility and other tests before. Doing amazing on a test isn&#x27;t always going to mean they&#x27;re going to be amazing at the job but if they do badly on the test then they&#x27;re probably not worth continuing with. Tests like these act as a good automated time saving gateway to filter out obviously unsuitable candidate as conducting good interviews takes up a lot of time. You can learn a lot from their test answers as well; chatting to a candidate about their code in the interview can be a good way to understand their coding experience.<p>By the way, when reviewing tests answers, I always tried to be realistic and not penalise someone too much for e.g. missing a subtle optimisation trick or slightly misunderstanding the problem.