Interviewing is really tough. The OP replaced some coding questions with other questions and if he were to interview a bunch of people with them, we'd get another set of blog posts complaining how ridiculous his interview questions were. "Why is it bad to write a file to the disk one byte at a time?" What are they interviewing for, low level disk experts? "Here's a stack trace from an open source project, can you tel…
Writing one byte at a time is a pretty quick way to ruin flash on a mobile device (or really, any flash).