The interview was a 3 step process. An phone call with the recruiter, an online code test via HackerRank with 2 of their developers, and an on site interview at their HQ in Amsterdam. This consisted of 3 separate interviews, one with their recruiter that explains their relocation package, working at booking etc.. And two 1hour interviews with their front-end team.
1. The phone call with their recruiter is fairly standard and is mainly a discussion about your experience and a few questions regarding A/B testing.
2. The technical interview online via HackerRank consisted of introductions, talking about your experience and a programming question, which in my case was to create a form and a generic function with which to validate it. The two developers were responsive and happy to answer any questions.
3. After passing the technical interview online, you are invited to visit their office in Amsterdam for which they cover your flight, and accommodation which is really nice. Usually you get a couple of days to explore Amsterdam, and then spend 3-4 hours in their office for the interviews, and lunch with a member of the team.
3.1. The interview with the recruiter was more of a discussion where they aim to explain what it is like to work in Booking, how they would handle relocation, and various benefits.
3.2 The first technical interview was with two of their developers, and there was a little bit of a language barrier there as they were not native English speakers, and I unfortunately do not speak Dutch. You are required to write code on paper (which you are told before flying to Amsterdam). The question was to create a generic tooltip for various DOM elements. So how you would tell this function that you want a particular node to have a tooltip, specify its content, and implement it via javascript/jquery. I'm fairly certain this is where I fluffed up since I over complicated the solution a fair bit, so keep things simple.
3.3 The second technical interview was with two different developers, and consisted of a few questions. The first, you are presented with a list of tasks, and you are asked to prioritise them and explain your reasoning behind your decisions. Then the technical question was to create a dropdown navigation component. And the last question was to generate a stock 'widget' where stocks are retrieved from an API in a format of your choice, which you had to poll and update the UI with the latest values.
Overall it was a very enjoyable experience, though I unfortunately did not get an offer. Everyone I have talked to was very nice, and it gave off a very positive vibe. So if you're considering it, I would strongly recommend it.