This might be unpopular, but I think this is a problem that can never scale well. It is possible to get to know someone, and spot incompetence or deception; but it involves spending time with people. Once you scale you need an objective measure, such as testing, an testing has some specific failure modes. On a smaller scale, human intuition and appraisal can work more effectively. I know someone is going to point out that these can be very limited and biased. This is true, but the "objective" and "merit-based" systems don't seem to be winning over anyone either.