Hi, I just test the DepartmentListViewControllerTests in simulator, iPhone7Plus, iPhone6s, iPhone5s, and the time difference between testTotalEmployeesPerDepartment() and testTotalEmployeesPerDepartmentFast() is really small, wonder why this happen?
Yes, I tested the final project with simulator and iPhone7Plus.
The tests run pretty fast. You would need a bigger data set, not just 50 employees in 6 departments, to really notice the difference. Try 5000 employees and 60 departments and it would probably be pretty obvious.
This was on the XR simulator: