Process took 2 weeks. Applied through campus recruitment and was invited to an online assessment test. The test was numerical, not too difficult, but would require you to pace through. One week later, got an email invitation to assessment centre in London. The day started from 9.30 am. Introduction session followed by two tests. One numerical with no calculator and a verbal (GMAT style), both 30 questions in 30 minutes if I recall correctly. Very time-restricted. After that, we had lunch with first year associates. Afternoon included a group case then a written exam. Had to summarize an economic article (more like a story).