1. TA Interview 2. Hiring Manager Interview 3. Real-time Problem Case Study 4. Case Study presentation to Hiring Manager and Director 5. Interview with Senior Director The idea seems to be to give a real time problem and get a solution for the problem for free. They will ask to share all the excel sheets you have created for the case study problems. Once they have understood the solution and since you have already provided the complete logic, algorithm and all the formulas on excel. They will simply get their solution for free and merely automate it on their system.