The problem is that those things can be faked during an classic interview by a good actor (or "salesperson"). It's much harder to fake problem solving skills on

The problem is that those things can be faked during an classic interview by a good actor (or "salesperson"). It's much harder to fake problem solving skills on a whiteboard. The pair programming approach is not terrible, but might be problematic if skill fields (technologies, environment) of interviewer and candidate are not perfectly aligned. So either the candidate will have to work in the company's setup they're not familiar with, or the interviewer will try to follow something they don't easily understand.