I completed an undergraduate internship with Metaswitch 2 years prior in the same position (Computer Engineer) and was placed immediately into the final stage of the process when I contacted my internship mentor for referral into a graduate role. They called me to discuss a suitable date 2-3 weeks in advance, and the interview(s) only took one full day (9am-4pm). This day included firstly 3 different written skill tests followed immediately by 1:1 discussions with senior employees of the company where I had to explain my solution and develop it further as much as possible. Between these tests, I had to hold a pre-prepared 30-minute presentation on a topic of my own choice (they advise doing it about a hobby or passion) and I had 2 or 3 short 1:1 interviews about my career motivations and aspirations. They also invited me for lunch at their canteen during which I had the chance to ask questions from a recently joined graduate. Overall, the interview day is very demanding, but in a good way - they really want to make sure you are a good fit, and you should also make sure Metaswitch is a good fit for you. As I understand, the company rewards your loyalty, so if you hope to do many things in your early career and don't want to settle in, this company might not be for you (just yet).