Assessment centre with about 15 other candidates - day consisted of group exercise, individual interview and individual presentation. Exercise was more a puzzle-solving task which was a pleasant change to the standard group tasks in other ACs. Interview was about an hour long, questions about you and your previous experience. Presentation was structured into 30mins for preparation and then presenting your idea to assessors - no slides required, more of a meeting to discuss your idea and be asked further questions about it. Overall a very enjoyable and interactive, albeit long, day. Very poor feedback process - ie instead of receiving a phone call as was advertised in both the case of an offer or not, got sent a very brief automated email. Also advertised was the opportunity to receive personal feedback - after 3 months of emailing asking for at least some brief feedback, got no response. Process of applying to O2 was otherwise very smooth.