It was a required position to take as part of the graduate program, so there was not really a interview process, but to get into graduate school you must have the minimum required GPA for that year to get in, I believe you had to submit a CV and cover letter as well, and upon acceptance you must find a professor who you wish to work for.

Applied online through a dedicated website, which automatically groups the best candidates into a pool that goes to the professor of the course for final selection. The position is unionized so if you have previous experience bing a TA that is usually very helpful in getting a job. For first time applicants, it helps if you know the professor as they have final say on the recommendation.