[jim_greco]

In my experience in finance it's all about the interviewer showing the interviewee how smart she is.

There's smart quants/programmers/traders/etc and people good at solving brainteasers. You need the former, but people who use brainteasers in the interview process typically only find the small sliver of overlap in the venn diagram.

[silverbax88]

Brainteasers in an interview is a red flag that you probably don't want to work for the company. In my experience.

If you're interviewing someone and you're lazy enough (or not confident enough) in your skills at assessing a candidate, that's a weakness.