I applied online. The process took 3 days. I interviewed at Young Scholars Institute (Irvine, CA) in Oct 2019
Interview
The interview process went with the instructor asking a few questions about your academic background & history as a minimum of a 4-year degree or at least proof of completion within the near-future will be required for the position especially in the subject areas you will be teaching. You'll then be given 5 minutes to demonstrate a sample lesson in order for them to judge your teaching experience. The interview process went rather quickly and I was hired immediately after the entire process which took around 30 minutes.
Interview went well but afterwards I was given tests to complete to see if I know the material well enough to tutor in it. The tests were multiple choice and were taken out of a book which was for high school testing.