I was contacted by a recruiter from Google. We had a brief talk on Hangouts about the role and the interview process.

The next step was a 45-minute phone technical interview with an engineer. It was composed solely of data structures and algorithms questions. The engineer was not very welcoming and went straight to the point. I barely passed this stage, but I was given detailed feedback by the recruiter afterward, which was appreciated.

I was then invited by another recruiter to an onsite interview at Google Zurich. Flights and a one-night hotel stay were booked by Google, so there was little cost for those few days. I took the opportunity to do some sightseeing.

The recruiter took care of me throughout the day. I had two interviews in the morning, followed by a lunch break with an engineer, and then two more interviews. All interviews followed the same format: clarify, solve, and write code for a given problem. I was able to write code on a laptop instead of a blackboard, which I found very nice.

The interview questions were very hard, and Google expects you to go through and finish the coding within the allotted time. Some of the engineers were very friendly and pleasant, while others preferred to talk only about the problem at hand, which did not put me at ease. The lunch break was very nice and relaxing.

After the interviews, I had a coffee with the two recruiters, which was quite nice.

After a few days, I was told the results were not strong enough, with again detailed feedback.

Overall, it was a nice experience, largely due to the very nice and helpful recruiters.

Given a string, compute the length of the largest substring which contains at most k different characters.

Example: "aaabbbbbcc" with k = 2 -> 8