[kazinator]

I would say that even being demonstrably good at the job has an imperfect correlation with being productive on the job. Because people lose motivation and procrastinate.

A given programmer might blaze through an interview task like a superstar, yet take two days to get started on it if it's an actual job assignment.

Everyone can put on their Gets Shit Done hat in an interview, in other words

That is why interviewers ask questions about previous job experiences and contact references.