I applied to this position online for a six month placement scheme. I was then called up for a phone interview. I must note that the questions asked will be directly related to what you have put on your CV. I listed being proficient in C++ and a beginner in Java, and this was where the format of the phone interview went with.
The phone interview was mostly technical in nature. Nothing very difficult. Basic conceptual stuff like: differences between references and pointers, dangers of pointers, how to initialise references in a class, on multiple inheritance in C++, on some basic OOP concepts like encapsulation, abstraction etc, differences between new and malloc. Basically, if you have coded sufficiently in C++, the interview will be a no-brainer.
Then I was offered an in house interview.
The in-house interview took place at their corporate HQ in London. Three bunch of people you talk to: the junior developers, then a more senior developer and finally a recruiting team person.
The junior developers tested me on some code related to determining the type and values of some C variables. The variables were a mix of pointer arithmetic, character arrays and access arrays via index and by pointer arithmetic. They then asked me a simple algorithm on calculating the maximum consecutive recurring string of characters in a given string. Nothing too difficult. They asked some of the repeated questions from the phone interview.
The interview with the senior developer was slightly more difficult. He started out asking me on how I would calculate the square root of a number.
The final person during the interview was with the recruiting officer who asked me standard questions like why I want to work at Bloomberg, what I see myself in a few years time, and some questions on motivation and work ethics amongst other things like leadership.
Got a call within 48 hours on the offer.