Initial combined technical/competency based telephone interview followed by assessment day in Waterloo, London. As I live in Scotland they paid up to £150 for flights/accom. All day assessment with 5-6 person team exercise, followed by partner interview (to see if you are IBM material) followed by technical interview "grilling" (to see how you react to aggressive/negative questioning). Its all slightly odd as all candidates had 10-20 years of industry architecture experience and this felt more like a graduate assessment test. IBM are proud in that all staff regardless of grade have to go through this (apparently).