I applied through their website, filled out their forms, and after four days I received an email stating that the responsible recruiter would contact me soon. Three days later, I received a phone call. It was a general conversation about my availability to move to Amsterdam and scheduling a technical phone interview.

At the beginning of the interview, they asked me about my background in Perl. I answered that I had written a few scripts, so they switched to general programming questions.

The first question was to write a regular expression for zip codes. The second question was to write a program that takes two integer arrays and outputs the elements in two arrays while removing duplicates. For example, [1, 2, 3, 4] and [3, 4, 5, 6] should output [1, 2, 3, 4, 5, 6]. The third question was to write a bash script that mimics the find command, taking a root directory and a filename, and searching for that filename within this directory and its enclosed subdirectories. [hint: BFS ]

During the interview, they used Titanpad - a program for multiple people to work on a single document simultaneously - for the programming questions and to exchange code. However, this web application is really bad and kept losing connection.

After that, we moved on to database questions:

• What is a transaction?
• Why transactions?
• What is the difference between NoSQL and a relational database?

Last business questions:

• Where do we get our money from at Booking.com?
• Can you think of different business models with which we can make money?
• What do you think is the problem with each model?

What is the difference between NoSQL and a relational database?