[px1999]

As you probably expected from your phrasing/question, no.

Ultimately there's often some frustration from both sides when hiring. Interviewers get a ton of under-qualified candidates and need a way to weed them out. A semi-technical conversation isn't always enough (lots of practically useless programmers can repeat dogma). Stumping someone _is_ a good way to assess their technical capabilities (you get a nice mix of analytical thinking and creativity to try to come up with a working solution even if it's not perfect).

I try to tie my technical questions to previous projects/areas of interest, with increasing difficulty/complexity, but sometimes this is difficult (particularly if the potential hire doesn't have any particular specialisations). If you start too low, the interviews go too long and you don't get a good feel for what the person can actually do. If you start too high, it comes across as demanding knowledge of obscure algorithms. I know that I've unintentionally asked questions that have come across this way, but in those cases you can't really expect a full and correct answer -- all you can expect is an appreciation of the components and some thought on how the person approaches problems.

That said, if you're being hired for your specific pre-existing knowledge, that's a different matter.