What I found is far more important are social skills. Can the person work as member of a team? How do they respond to feedback? Or when something is hard? When they get stuck? How do they communicate a design? Rally a team around them? Deal with disputes? React to changing situations? Can they take the initiative or need to be told what to do? Etc, etc.
Together with actual coding/design skills - and with proper management - these are the necessary conditions. All my humble opinion, of course.