I was firstly contacted by a HR via email and we agreed for a telephone interview of the duration of about 1h15. The interviewer asked me about my master thesis and some other questions about a couple of points i mentioned in my CV. In a couple of days, after the phone interview they invited me for a physical interview at their location. The interview had the duration of about 1 hour and i was asked once again about my master thesis and some other points regarding my CV. I was also asked to solve a small numerical riddle in ten minutes and i couldn't solve it completely. After a couple of days after the physical interview, my contact emailed me for telling me they won't proceed with my application process.