During my phone interview, I was asked two questions: one easy and one hard.

The interviewer was completely silent during the interview and explicitly stated that they could not help or give any direction (aside from answers about the nature of the question).

I was stuck for some time on a problem during the second question and ran out of time. They politely answered my questions about Dropbox, but the technical interview was really disappointing.

Given a file path, determine if a given byte array exists in the contents of that file. The file is large, so you cannot read it all into memory. The search query may be as long as the file itself.