First they give you a general aptitude/problem solving test. After passing that, they give a more in-depth editing test. Then I had two in-person interviews. I didn't hear back for months after applying, but after I got the first test, the entire process took only 2 weeks or so.

Two steps of on-line email testing including a basic editing exam, proof reading, and some logic questions. Nothing surprising or difficult. Two in person interviews on separate days. Questions were the standard expected interview questions. Focus was on problem solving situations, client service issues, etc.. Interviewers were friendly and did not interrupt responses. They were interested in the answers supplied. Overall, a good experience.