The process was extremely varied in terms of how long it took to hear back after each step, ranging between two days and two weeks. I also felt passed around between a lot of recruiters.

After my onsite interview, I was asked to follow up with a second onsite. This was supposedly so they could ask me questions they thought would be more suited to my role. Then, it took a full week after that second onsite to finally get my rejection, which came by phone for some unknown reason. (Just reject people by email; it's easier for everyone!)

I thought that the second round of onsite interviews actually went better than the first. This begs the question as to what exactly I could have done to get the offer in those second-round interviews. Why were they necessary?

Google says they just look for good generalist programmers. This would seem to be called into question by this process.

To sum it up, the people were generally nice, but the process seemed irrational and unnecessarily long. I can't help but feel like my time was willfully wasted.

Mostly classic computer science (cracking the coding interview) types of questions, with some added twists to make them harder.