After application, online assessment and phone interview with personality test (pretty simple, directed at your ability to be international and proactive), there is an assessment center to attend outside London at the HSBC training facility. On the first day it's all good fun, but on the second day the process starts with a load of papers that are not in order, refer to three different projects and are pretty hard to get into a decent context. There are three parts to the day, where these documents are relevant, and one interview pretty much repeating the personality test originally given on the phone. The three parts relate to the same company. One is the choice of a consulting firm, one is the choice of a location (team discussion and decision, GRADED!!), and an interview (you interview somebody to find problems and solutions in the company). Finally, there is a synthesizing presentation of the entire thing. Start preparing that early, as they will let you know that you have to do this only shortly before you have the meeting.