I applied through university. The process took 1 day. I interviewed at Arm (Cambridge, England) in Nov 2015
Interview
For your given teams that you have been given you get interviewed. You get lunch and shown a presentation and you are introduced gently before being interviewed. All the questions were technical some were asking for specifics and others were open ended. They also asked about what you knew about ARM and how they operate.
After this stage I was given a series of "soft skill" questions to answer online on video in my own time.