Process depends on the department and position. Some departments require completing a test that involves analysis, writing, editing. Typically interview with several people at different levels plus HR to give an overview of the team and organization. Interviews are several hours long and may require 2 visits on different days. The point is to give candidates a good idea of the environment and culture and for the organization and department to assess "fit" as well as expertise.
Interview questions [1]
Question 1
Describe a project you did that went awry and why
Describe a project in which you received surprising extensive critical feedback