The interview process consisted of:

• Sending your CV through their careers website.
• Completing an online Computer Science/programming test.
• Three on-site interviews.

1. There's not much to say about the first phase: you send the documents, and they get back to you, possibly with a link to their test (which you have about 3 days to complete).

2. The test consists of 30 multiple-choice questions, each with 5 answers. There are 3 minutes for each question, and you cannot go back. I don't know if speed is a factor in your assessment. At the end of the test, you get your result. Again, in a couple of days, they get back to you. If you were successful, they invite you to their office.

3. The first interview is with two junior developers, the second with a senior developer, and the final one is with HR.

The technical questions involve much rather low-level concepts. Implementing compilers, garbage collection, data structures, solving algorithmic problems, analyzing complexity, and memory management in C are a basic list of issues that were covered in the two interviews. Know your stuff and be confident; they will challenge your choices and decisions, even if they're right. They want to be sure you know why you made your choice, that there is a good reason, and that you can explain that reason.

Generally, I liked the process very much. It's down to earth. You don't need to write a novel answering pointless questions in a 50-page application form. The technical questions aren't concerned with knowledge of syntax but with concepts. The people I had contact with were extremely nice and provided exhaustive answers to all my questions (and I had a lot of them).

How would you implement a garbage collector?

Explain the most popular approaches, discuss their pros and cons.

Discuss the data structures you would use for the implementations and the reasons for your choices.

Given an array of integers, provide an efficient way of finding an integer that appears only once in this array.