I applied through university. The process took 3 days. I interviewed at The Johns Hopkins University (Baltimore, MD) in Jan 2015
Interview
They told me to come to a room to interview. They asked me some trivial questions like why you want to work for us, and what you would do if a student ask for help. They care more about what you have taken for courses, especially the one you are about to become a course assistant for, than how you do in your interview. Basically, if you get an interview and don't do stupid things, then you are in. Others might beg to differ, but that was my impression.
I applied online. The process took 4 weeks. I interviewed at The Johns Hopkins University (Baltimore, MD) in Jul 2023
Interview
Short interview with questions asked about scenarios with students and how you would go about handling them/teaching the student. No questions were asked about technical eligibility or subject knowledge. Overall, interview was very fair.
Interview questions [1]
Question 1
How would you help a student come to a conclusion without giving them the answer?