Barclays Summer IBD (London)

After online app, tests etc. there is an assessment day which consists of a presentation and interview. For the pres, make sure you go through an IB Guide (e.g. Vault, CityCareersSeries, BIWS) as the technical background will be needed to show you have done your research and know the basics of banking: debt vs equity, pros and cons of M&A, etc.

For the interview, a lot will be motivation/competency-based. I was asked one technical/brainteaser-y type question that was testing how good I was with big numbers (12 orders of magnitude) and the concept of leverage. But you must be familiar with the firm's values and all of those wishy-washy competency questions. Above all be enthusiastic as I was actually dinged for lack of enthusiasm despite nailing everything else.