We have the candidate sit at a workstation and write a functioning program to solve a relatively realistic but self-contained problem using the language of thei

We have the candidate sit at a workstation and write a functioning program to solve a relatively realistic but self-contained problem using the language of their choice. It usually involves extracting and working with some data from a few big CSV files -- we have pretty legitimate datasets set aside just for the interview. There really aren't any restrictions during this: the candidate can use any resources they would normally use, including Google or Stack Overflow. We don't have the interviewer watch everything they're doing over their shoulder. They're allowed to just work on the problem on their own.