Booking.com Software Developer - Willing to Learn Pearl interview questions

1. Submit CV through website; 2. Email contact to schedule a phone interview; 3. Phone contact from HR employee; 4. Technical interview online with 2 tech employees; 5. Email - negative response. HR interview: Why do you want to work for us? What do you know about B.com? Technical interview: write an algorithm that displays the combination of 4 strings A B C D A B C A B D A B B C D B C B D B .... and so on