It was online interview on Skype. 3 interviewers in total and they all asked question from their field in relation to what I mentioned on my CV. It took about an hour until they decided to stop and told me they will contact me with result in next couple of days. They started by asking me to describe myself and what I have learned previously and then with clock the interview went more technical to the end.

Java Questions, all OOP principles and few Thread related questions.