After sending in my CV and having a short phone interview, I was invited into the main ARM site to have a technical interview. I had two interviewers who were very easy-going and helped me through the 3 questions that they asked me. The questions were fairly easy with some ground to have a conversation about the solutions. At the end of the session there was a chance for me to ask some interviewers some questions of my own (I could have been better prepared for this as a sharp question gives a good impression).