IBM Sr. Consultant interview questions

Responded to agency job advert on jobsite web page, sent them cv with a cover letter online, got a phone call later on in day from agency stating they'd liked my cv and sent it to IBM for review. Got phone call from agency abotu a week later asking for availability for phone interview...phone interview took place about a week later, was very technical, questions about specific software and techonologies ( websphere, MQ, windows, unix ) . Did okay, was told they'd arrange a 1-1 interview...took another week, went to South Bank offices, was a 3-1 with one techie ( same one who phone interview me ) , my potential manager and a HR type. Some more technical questions then a wlkthrough of my CV followed by loads of "what would you do" & "describe a situation where" from the manager - lasted just over an hour. In the end I was told there and then they would offer me the job and then HR bod went into pay and package. As job was advertised with pay at £45k - £55k, I asked for £55k as I had all experience and skills they were looking for already. Luckily they settled for that. Got an official letter of employment about 2 weeks later ( had to chase them up a couple of times though )