I applied in-person. The process took 3 weeks. I interviewed at US Navy (Dubai) in Apr 2015
Interview
Easy. I submitted my instructor package. It came back approved because of good evals and strong recommendations. I was asked questions by the lead instructor. My attributes were a match for working as an instructor.
I applied through a recruiter. The process took 4 months. I interviewed at US Navy (Washington, DC) in Jan 2021
Interview
They asked technical questions to get a good understanding of where you are at for Physics and Calculus. The occasional additional question may be asked about your previous performance in school or your ability to teach the topic at hand.