The process consisted of two parts.

I submitted my CV at a job fair organized at the university. I was emailed that night to have an in-person interview the day after, which lasted less than an hour (with two interviewers).

After that, they let me know in a couple of days that they would have liked to meet in person for the second part of the interview. In about a week, we organized the trip to Amsterdam.

The second part consisted of three interviews plus some HR questions (like "why Booking?").

• The first one was a 1-hour technical interview, pretty similar to the first one. The interviewers did not put much pressure on me while I was solving the problems, but they did question my decisions and asked what other choices there would have been and why I didn't pick them.
• The second one was again a 1-hour interview, this time more focused on the design of components and the architecture choices to make. Both these interviews were with two interviewers, who were developers. They wanted me to be extremely precise in the system I was describing (I explained the same design in three different ways). I don't think I performed too well in this part.
• The last one, also 1 hour, was about business understanding. This time it was one-on-one, and the interviewer was the lead of team leads. It was a really relaxed and interesting interview, where he asked me if I knew the business model of Booking.com, what I would have changed on the site (asking to elaborate quite a bit on my replies), and how I would decide if a feature under testing should be made permanent or not.

At the end of the interviews, they showed me the building.

In a couple of days, HR called me to tell me they liked me, and she sent me an offer.

Call a function F in a loop.

F returns a string of 140 characters. Write to the output '1' when F returns a string with the same letters (basically a permutation) of a string previously returned. (The original question was not well-formed.)

Given a map of user to a list of locations, write a function that takes a location and suggests what the next location a user would go.