Initially, PROS does a phone interview to look for initial fit. If you pass that, they will bring you in for in person interviews with various individuals of different levels from across the organization. This gives PROS as well as the individual a feel of each other. You usually interview with 3-6 people and then wrap up the interview process with a presentation in front of 6-10 people on any subject you find interesting. The main goal is to see your presentation skills and your comfort fielding questions.

5-6 back to back interviews and one presentation, there isn't a fixed group of people conducting the interview so it depends on who you meet the questions will be different, but you should always know your applied position and prepare accordingly, presentation skills definitely help.