It was a very informal interview with 2 interviewers and they asked technical questions (which I really did not expect) which require a pen and paper to answer. Its alright not to know the answer in the beginning but they will guide you and give you hints to the answer. With knowledge from what you've learnt in some of your modules during your degree in university, you should be able to answer eventually after linking the concepts you have learnt plus the hints they have given. However, interview process may vary depending on what department you apply for. The interview was really very tiring and demoralizing as I couldn't answer any of the technical questions the interviewers asked in the beginning. So I thought I really screwed up the whole interview. But I managed to answer all their questions in the end though with their help and guidance. I think they want to see how your character is like when you face a problem and whether you are able to apply the concepts you learnt in school to a problem you might face and whether you are able to link all the concepts you learnt and hints they gave to solve a problem.