I had a phone interview with a small startup for a Web Development role. I was fairly confident that I would pull through most of the technical questions that would come my way.

They instead asked me a stupid optimization problem involving some buckets, pigs and poison. I answered it, told them to fuck off and ask me something relevant.

Except that I didn't. I fumbled to find a half decent answer to it and they were unimpressed. The worst part was that I could think of a dozen better answers after the call was over.

Doesn't seem particularly fair for people to judge you by such abstract questions rather than evaluating skills directly relevant to your job.