I was originally set up with two phone interviews, back to back, at a time convenient to me.

The interviewers really just want you to show what you know.

My second interviewer started asking questions on material that I hadn't learned. Instead of failing me, they set me up with another interview a few weeks later.

The interviews were done on the phone, using a shared Google Document to show work on. There were two programming questions, pretty standard, having to do with data structures and algorithms, that sort of thing.

In one of the questions in the interview, they asked me to build a tree iterator for a binary tree.

Given a list of strings, return the substring representing the longest common prefix.