Mix of coding, numerical and logic based questions in the first couple of stages. Then on to a culture fit and final technical interview. It's a long process but they are very responsive and the questions are quite fun.

Neptune is pretty data driven when it comes to hiring, as they have a clear idea of what type of person they want working there. To their credit, everyone in the process was highly professional and the employees who interviewed me were rigorous and exceptionally intelligent. They have a high standard and it can be tough. That said, the resulting diversity of the teams is low - both from a personal and professional perspective.