The application consists of several steps, after your resume and motivation letter has been considered. First, there is an online skill assesment in the form of several mini-games. Those are used to map your strength and weaknesses (I think it was kinda of accurate), and verify if you indeed fit for the job. Afterwards you are face with a brief online interview (registered), you have to solve really basic problems in a short period of time and answer some questions about your interests/expectations and so on. The real challenging part come next. In the third part of the interview process you are faced with an online Q&A. The problem range from "finance" knowledge, expecially how a "Market maker" operates in detail, to logic/mathematical problems. They expect to see speed in execution, a fair amount of precision (you don't have to be perfect) and a prompt reaction to errors made. I know the interview process would continue with at least two other board of examiners