They sent me a letter for attending the interview. I met with the IT manager (who was my direct line boss) and he interviewed me. It was quite informal (bare in mind it was for an internship) and he asked me some general technology problems. He talked about the role on offer and described what my typical day-to-day tasks might be. He then went on to talk about specific projects that we wanted done over the longer-term. He made it clear that I could fit the job to my interests (to some degree) and I could (e.g.) choose the language to program in for X,Y,Z tasks. Then we talked about lunch time activities available (they provide football as in-house exercise excursion).

Call interview, then go to second stage. From my research.. i see other candidates go through until 7th stage for this position. Hard interview session but worth if you get into the organization.