If the purpose of #3 is to get a true reflection of what the person is actually like then don't sit in a board room and ask them obscure Fermi questions. Meet

If the purpose of #3 is to get a true reflection of what the person is actually like then don't sit in a board room and ask them obscure Fermi questions. Meet them in a local coffee shop, bar, tech meet-up, etc. To get the candidate to step away from work-mode you need to step away from the place of work. It really is as simple as that.