I am fond of design questions, both on the receiving and asking end. I drill down until you take a branch that I would distinctly choose not to. Then I press you for reasons. E.g., why would you write your web app in C++?
edit: Note that someone who is genuinely very close to me in opinions won't challenge me in ways that really produce a useful diversity of opinion. They would, however, likely agree with my sense of strategy and tactics; this might lead to a collective blindspot where a deeper problem is overlooked. Being able to professionally disagree and then work together to form a final result is very important.
