I applied online. The process took 3 weeks. I interviewed at Bloomberg (London, England) in Feb 2015
Interview
I went through three rounds (out of four). All interviews lasted less than 1 hour. The other reviews are extremely helpful in order to prepare interviews. I would just highlight how important it is to review asset classes basics (bonds, options, etc.), specially if you don't have a financial background. Also you should carefully prepare financial news as you will be asked to bring out a relevant topic for you or prompted to discuss one of the interviewer's choice. You should have a good understanding of the most relevant topics, such as ECB's QE (try to remember some figures and specific facts), and also prepare something more focused on the specific region you will be working for, e.g. if you are applying for an Italian speaker position, mention something relevant about the Italian market.
Begins with a personality assesment that also includes puzzles meant to test pattern recognition. The assesment and the personality quiz takes about 30-40 minutes and requires no preperation before hand.
First was Hireview, 1 Hour interview with two team leaders, and assessment centre, consisting of tests, networking, and a final round interview with two team leaders from analytics and sales departments respectively.
Multi step interview process, they have you submit a recorded video interview, then you get selected for a virtual super day where they interview a bunch of candidates at once, then you get an in person. Know about finance and know as much as you can about Bloomberg and its business. Have a good take on AI in finance.