How can I know a job post is for l3/l4/l5? I see they have different requirements on years of experience. Does yoe requirement being 4 years mean l4 and 5 years mean l5?
I believe most companies, including pins setup how many coding vs design sessions considering YoE and relevant experience in the area. Leveling is done based on your interview performance although generally will lead to a down leveling if interviewers determined not enough chops yet but see potential.
This is generally never the way it's done, though I can't speak for Pinterest