The whole process took around 3 months, mostly due to New York holidays and delays related to visa issuance, shifted because of my vacation.

I was contacted by a recruiter, and we scheduled a technical phone screen with two engineers. It wasn't difficult; I was asked one coding question and standard questions related to data structures, Java, and Android.

The coding question was: Given three arrays, find all elements common in at least two of the arrays.

They also asked me to explain HashMap and SparseArray versus HashMap. There were a number of Android questions, such as what happens to AsyncTask if an Activity is recreated and how to design an app to handle orientation changes correctly in a multithreading environment.

After that, I was invited onsite to Amsterdam. There were three rounds, which took around 3-4 hours in total.

1. The first round was with HR. She asked me basic questions regarding why I wanted to change jobs and why I wanted to work at Booking.com. She also explained the relocation package.

2. The second round was with two back-end engineers, who gave me two coding questions: check if a string is a palindrome and write a function that returns a Pascal triangle's element for a given row and column. There was a simple question regarding a small Java code snippet about iterators, and we also talked about their business model, monetizing process, and A/B testing.

3. The third round was with two Android engineers. I was given a coding question to write a function that should return all contiguous subarrays that sum up to a given number, provided along with the original array.

Then we had a long talk about Android. They asked me to write a layout for a given list row of their listview. We discussed the listview concept and best practices for its implementation. I was also asked to design a listview that had to download images from the network for displaying them in every list row and to suggest ways to avoid unnecessary downloads when the user scrolls fast, to achieve smooth scrolling performance.

Surprisingly, there were again business questions, some of which were the same as I had been asked by previous engineers.

After that, the HR person suggested a final Skype interview with the hiring manager a few days later, as he was not available at the office that day.

The last interview with the hiring manager was quite difficult. It was almost entirely about their business model. He also asked me to compare different existing business models and suggest one that Booking.com currently uses. This was the most difficult part for me, as developers normally do not know such commercial details, but it appears to be a 'must-have' knowledge for this company, as developers there are also making a lot of business decisions.

Overall, I was happy with the entire interview process. All travel to Amsterdam was organized very well. I was especially impressed by the great work of the HR department; the recruiter was extremely open, polite, friendly, and cheerful. Moreover, I received a comprehensive report explaining why I was not selected, which is usually not disclosed by employers.

Compare different existing business models and suggest one which is used currently by Booking.com.