The process is in three parts.
The first part is a written exam, made of several medium length exercises. It tests the overall programming knowledge of the candidate and his capacity to quickly read code and reason about it. If you succeed, the HR department will call you rather quickly to continue.
The second part consists in an interview with the HR department. The goal of this interview is to check with the candidate if his expectations and those of Murex match, in term of position, role, salary, etc.
The last part consists of technical interviews (one or more) with the teams potentially interested by the profile of the candidate. Each team has its own preferred exercises and focus, so the difficulty, duration and topic may vary a lot. It is also an opportunity for the candidate to check whether he would like to work within this team.