Referred by a friend, I quickly got a phone interview one week after.

First, I described my current work, projects, and experience on my resume. Then, I was asked about the difference between interface inheritance and implementation inheritance.

The coding problem was simple: binary search.

Follow up with this:

Someone modified your binary search code, and the result is bad. The modified version may no longer be a binary search.

Create a test case to determine if the code is still a binary search without having the source code on hand.