I think coding competency is really hard to assess in interview, and arguably the wrong goal in interview. When I evaluated the real goal of interviews, it was

I think coding competency is really hard to assess in interview, and arguably the wrong goal in interview. When I evaluated the real goal of interviews, it was surprisingly not to discover the best coders, rather to discover the best fit for the team. Consequently a chemistry/collaboration oriented interview was the most predictive of long-term candidate success.