I was contacted by a Google recruiter by phone. My resume was on file from a previous interview three years ago, which did not result in an offer. We had a short conversation about what was available at Google and about my experience. The questions and information were very high-level, and it didn't seem like this was even a phone screen of any sort.

She then passed me on to the HR person at the NY office. I was told that there would be a phone interview where I would need to be at a computer and would need to be able to code. However, since I had already been onsite previously, they decided to skip this. I was handed on to yet another person to actually schedule the interview and then back to the HR person.

The onsite interview was from 10 AM to 3 PM and consisted of five interviews and a lunch conversation. Each interview was 45 minutes, and they ran pretty much right on schedule. They were difficult but pretty much what was expected. There was almost no discussion of work history or anything other than technical questions. Most of the time was spent at the whiteboard, working on and then refining the answer to a question. They mainly focused on data structures and algorithms around them, things like BSTs, hash tables, and tree traversals. The questions were not standard algorithm questions that you tend to see around but were a bit more involved. They were interested in my speaking about the algorithmic complexity of my solution and how to choose appropriate data structures. Hash vs. BST came up a bit. The coding that had to be done was a bit awkward for a whiteboard; the solutions were not necessarily short.

One interview revolved around a higher-level system design question that was refined throughout the discussion. There was very little to no time to ask questions or discuss working at Google, and the interviewers did not seem interested in selling me on Google. The lunch conversation was not an interview and did not contribute towards the assessment. The person I ate with was very nice and seemed honest about the way things are at Google.

Over two weeks after the interview, I was contacted with the rejection.

Overall, the process was smooth, and people were helpful and nice. Though I did not find anyone to be particularly interested in selling the company. The interviewers were hard but fair for the most part. One interviewer did not describe the problem particularly well and had me coding a solution to the wrong problem for a while.

General algorithm questions, particularly focused on algorithmic complexity.

Know average and worst-case time for operations on hash tables, trees, etc.

The questions are not puzzles, and if you know your data structures and algorithms, they aren't too hard.