Shed roof structure

Shed roof structure. Considering strength as to snow load, North country.
I have been calling out ledger boards nailed and not bolted to structure, and /or rafters that are nailed without joist hangers. These issues can be of various pitches, rafters 16 or 24 on center, and any size field. I see this often even with so called building contractors.
I would not want an unwanted future failure to happen. Any thoughts on the matter?
. Steve

It’s all in the code book for residential building code. Ledgers must be bolted every x distance and no less than 2" from the top or bottom of joist. Yes joists should be hangered and h2 or a35 clips.