I am applying to KAUST's electrical engineering master's program. I had my technical interview through Skype. I want to share what it was like to help out anyone wishing to apply to KAUST.
You will be contacted for the technical interview via email. The email will include a list of topics to study and resources (books and links to material). The four main topics are: calculus, signals and systems, linear algebra, and probability.
During the interview, the interviewer will send you pdf documents wth questions pertaining to each topic in them. For some topics, you will be asked to explain how you would solve the given problems to the interviewer, without actually solving them. For other topics, you will be given 15 minutes to solve the given questions after which you tell your answers to the interviewer. You may be asked additional related questions. The interviewer is trying to test the extent of your understanding. In my case, the calculus and signals and systems were discussion type questions whereas the other two topics were done in the 15-minute answer and tell format.
Overall, it wasn't hard, but you should study well enough to be able to solve simple problems related to basic concepts.
I wish everyone all the best