Whole process took around 3 months, mostly because of NY holidays and delays related to visa issuance shift because of my vacation.
I was contacted by the recruiter and we scheduled a technical phone screen with 2 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 3 arrays, find all the elements which are common in at least any of the 2 arrays.
They asked also to explain HashMap, SparseArray vs HashMap. There was a number of Android questions, such as what happens to AsyncTask if Activity gets recreated and how to design an app to handle orientation change correctly in multithreading environment.
After that I was invited onsite to Amsterdam. There were 3 rounds which took around 3-4 hours totally.
1st round was with HR. She asked me basic questions regarding why do I want to change a job and why do I want to work at booking.com. Also she explained the relocation package.
2nd round was with 2 back-end engineers, who gave me 2 coding questions: check if the string is a palindrome and write a function which returns a Pascal triangle's element with given row and column. There was a simple question regarding small java code snippet about iterators and we also talked about their business model, monetizing process and A/B testing.
3rd round was with 2 Android engineers. I was given a coding question to write a function, which should return all contiguous subarrays which sum up with a given number, provided along with the original array.
Then we had a long talk about Android. They asked to write a layout for a given list row of their listview. We talked about listview concept and best practices of its implementation. Also I was asked to design a listview which has to download images from network for displaying them in every list row and I had to suggest ways to avoid unnecessary downloads when user scrolls fast to achieve smooth scrolling performance.
Then surprisingly there were again business questions, moreover some of them were same as I had been asked with previous engineers.
After that HR person suggested to have the last skype interview with the hiring manager a few days later as he was not available that day in the office.
The last interview with hiring manager was quite difficult, as it was almost about their business model, also he asked me to compare different existing business models and suggest one which is used currently by booking.com. This was the most toughest thing for me as normally developers do not know such commercial details but it appears to be a 'must' knowledge for this company as developers there are taking a lot of business decisions as well.
Overall I was happy with the whole interview process. All the travel to Amsterdam was organized very well. Especially I was impressed by the great work of HR department, recruiter was extremely open, polite, friendly and cheerful. Moreover, I received a comprehensive report about why I was not selected, which is usually not disclosed by the employers.