I hired a lot of very good developers, so I was able to rely on my intuition pretty well. Then one time I hired an excellent candidate, technically very strong

I hired a lot of very good developers, so I was able to rely on my intuition pretty well. Then one time I hired an excellent candidate, technically very strong. Then it turned out he couldn't figure things out on his own. I had a co-interviewer who also thought he was very strong. In the end we had to fire him after a month since he couldn't pick up the pace (his colleague who started at the same time is actually very good) I was "very good at hiring", until I hired the wrong person. Even now it's hard for me to tell what actually went wrong there. It was mostly theory and understanding underlying concepts, but now I definitely mix in a lot of practical issues and examples. Sometimes I think we interviewed his twin brother who could actually program ;). Hiring developers is indeed very difficult. You can only tell when working with them for a few weeks.