No assessment centres or team exercises, only face-to-face interviews after the video stage. All interviewers were extremely nice and genuinely interested. All questions asked were either based on my CV, or have been previously posted on Glassdoor, which is probably the best resourcefor preparation. Main point is articulating your motivation to work for the company and knowledge of the market environment, products, and competitors. At least perfunctory knowledge of the Terminal and some commands is also quite helpful. A lot of articles on Bloomberg and its history from the FT/Politico/Institutional Investor et al. are also recommended.
Overall, the interviews were extremely easy, no hardcore knowledge of finance is required (I mean, if you say you're interested in finance and don't know what a CDS is, you may need a reality check). HRs are very efficient: feedback is given the following day. Plus you can help yourself in the pantry (yay, free snacks).
9,5/10 would interview again