Maybe we are somehow insanely good at interviewing engineers, but after a standardized 1 day interview I can't think of a single bad engineering hire we've made

Maybe we are somehow insanely good at interviewing engineers, but after a standardized 1 day interview I can't think of a single bad engineering hire we've made in the last year. But, it may be much harder if you're only looking in the pool of people who are willing to work temporary contracts for $25/hour or "who are in jobs where they are unhappy".