Google's interviews have multiple tiers.

Tier 1 is a phone interview: 45 minutes with one person, followed by 45 minutes with another.

I was only able to get through the first tier. I had an interview scheduled for the first week of December 2017 and felt it went really well. Aware that Google employees might be busy or off for the Christmas/New Year break, I did not contact my recruiters or interviewers.

Three weeks into January, my recruiter called to say my interviewers had not yet responded regarding my interview, but they were sorting it out. A couple of days later, I received an email for another interview, but it was the same exact format as before.

This led me to conclude that my interviewers had lost the information from my initial interview. I was bummed about this because I felt I had performed much better on the first one than the second.

Things happen for a reason, I guess.

The questions I received were all similar to coding projects you would encounter in a 200-level college course. Once you answer those, they will proceed with more complex questions and, if you have time, even some algorithm analysis on your code.