Am I the only one who enjoys programming interviews? Even if you screw it up, it's still fun to try your hand at whatever problem they give you. They also don't expect you to do it perfectly; you're allowed to have sub-superhuman performance.
Unfortunately by 7pm or so I was sorta exhausted (didn't sleep the night before 'cause I was so excited). I met the hiring manager, and he asked something fun like make a ring buffer and also write a non-recursive inorder traversal function of a binary tree. I apparently had some off-by-one bug in the ring buffer code, and then I just blanked out on the traversal question. No hire :\.
(OTOH, that team wasn't sure if they were going to be using VB6, or C++, or maybe .NET, but probably not because they wanted to ship with Office and Office severely limits dependencies. So maybe it was for the better.)
It's great if you can have a reasonable discussion that actually shows your knowledge.
Part of the interview process is trying to find out what type of person you are dealing with.
I also sense lot of "entitlement" in OP's post and comments on this thread. It's like "oh I can't answer your interview questions but I'm so good that if I don't get the job, it would be only because your interview process sucks". Most company's HR would let you know what to expect at these interviews. If you are not comfortable with CS whiteboarding questions then you should just decline at that point. It's unprofessional to blame their process after you accepted to go through it, failed and then shit all over it because you didn't get the job.
This is not to say all interviewers are good and many could be downright assholes. But that feedback should be between you and their HR. It's just professional courtesy considering that these companies don't post on Internet how badly you performed on interviews compared to their other candidates to tell other side of your story.
Personally I like solving computational challenges whether I get job or not. As a programmers we are supposed to be loving these kind of CS puzzles. If nothing else, you walk out with few CS things you didn't knew before which would have taken same amount of time to learn anyway. I'm not saying interview questions shouldn't be job related but the fact is that many of these companies are doing LOTs of things and they need to hire more generally because they give you relatively more freedom to move around once you are in. So large companies have to keep things general at some level unlike startups with one project. In any case, if you complain about having to write code and design algorithms at developer interviews then you are probably applying for the wrong job.
I want in implementation of a high performance octree. Do it for me. Apparently you love doing this sort of thing for people who don't pay you.