I previously attended a BarCap Tech AC and was unsuccessful due to lack of technical knowledge (my CV actually screams business analyst, been years since I did programming, fair enough mind, they stated at the start of the AC they were looking for front office developers…), so make sure you are sharp when it comes to your technical knowledge, reviewing a bit on Data Structures/Alogrithms/Performance Enhancement would be my advice, just to ensure you can speak about that area comfortably even if you are not 100%. Mind you, some of the others I spoke to didn’t get questions on data structures etc. but certainly programming concepts were mentioned and are important. I actually get the feeling I would have got through this interview having re-read an old textbook on data structures and algorithms/basic java programming, I would encourage you to do the same if you have the time…
The interviewers for technical actually specifcally said “so we see you have experience in Java” when there is actually no mention of Java on my CV/application at all, so make sure you know one language as even though you might select a “general” technical interview you will be quized on programming. Having said all that, it sounds like your technical knowledge is probably up to scratch anyhow, so moving on…
In terms of competency - you have two interviews, one technical and one competency based. The competency interview is very similar to the telephone interview, but there are no questions on why BarCap etc. at least not for me - one or two got asked who the CEO was I think, so make sure you know that stuff just in case. But generally you are looking at examples of being in a team, how did you work, leadership, when you failed, innovation, how did you cope with team mate issues, how you deal with money (this is a strange one, think they are looking to see how careful you are with money or something similar) etc. I got very decent marks (one of the graduate guys gave me a phone with feedback, really great there for that kinda thing) for this, mainly because I stuck to work experience examples and have done 12031232 of these interviews before… Just be confident, speak clearly and get to the point, don’t go off on a tangent. You can view this as an extension of the telephone interview, although it varies from interviewer to interviewer as to the exact questions you will be asked.
As for IB knowledge (having just read your post again :D) I did not get one question about IB, nor did anyone I spoke to - nothing about what they do etc. I would still advise you know your stuff there though, perhaps even a few current events which are not hard to work out. Actually - thinking about it, they did ask about current technology trends and it would obviously look better if you linked that back to IB. There was a guy in my group who went off on a tangent about HFT, clearly not really knowing what it is, so if you do read up on something make sure you have a decent understanding on it. I won’t tell you what I spoke about, but generally it is not difficult to discuss current issues in IBanking and how technology can help (or is actually supposed to help with regulations etc.).
The group exercise was a nightmare for me, in a group with people who appeared to think it was a contest in getting heard, constantly talking over people etc. I would advise you to make decisions quickly and develop good reasoning behind those decisions, they will question you no matter what you say and expect you to speak up for yourself and not get bullied, same for the individual task. No point in saying more about those two areas, make sure you do the usual time keeping thing, put forward a few decent points and listen to others, standard stuff.
I got the impression the group project was just making sure you are not an arehole (I think they have a “no-jerk” policy, seen that advertised around on Vault) and the individual exercise was assessing your logic, again making sure you stuck by your decisions… I was only satisfactory in the group project as apparently I became flustered when asked questions (was actually embarrassed at how sht we were, although time is VERY limited so most teams struggled from what I heard), which was fair enough overall, had a 'mare.
Individual I did fine, just make sure you have logical reasons as to why you made certain decisions and stick by them. It is a strange exercise as the scenario is supposed to be meeting your manager, which presumably means you should take their advice and adapt, but they are expecting you to stand up for yourself too. You get 15 minutes to make the decisions, make notes next to each item to say why you would leave it (it is a basic task prioritisation exercise, pick 5 from 20 etc.) and then why you would select the 5…
It was a strange experience in a way - it is the first banking AC I have been to, previously I went to a Cisco AC which was very similar only EVERY interviewer saw EVERY candidate which I personally think works better. Hard to judge candidates when you only see a couple each and the questions appear to vary. Having said that it was a positive experience, even though I did not get the offer I felt I got a decent amount out of it and will use that knowledge (i.e. my weaknesses) going into the next couple of ACs I have coming up.
Additional tips - there is a networking dinner thing toward the end, DO NOT go for the lasagne, it is rock hard and makes you look silly trying to eat it with a fork and getting no where :D. I do encourage you to go around and talk to as many people as possible, be polite and discuss the day, be positive throughout too, I made the mistake of telling one of them I felt the group thing did not go as well (which is true, but if it comes to them deciding your fate you don’t want to give them something…).
Usual closing advice - be yourself (unless you are a jerk :D), be polite, be calm, do not rush, do not become flustered. They are not looking to catch you out, they are decent folks and you should be fine if you follow the advice on this forum!
Good luck buddies