Hard to believe that's all you need to attach the stringers. And why are the stringers so low to the deck? There is only a few inches butted against the deck. I just assumed it should be the entire length of the stringer. This way, you don't need the backer board. Would that be true?
I like it but structurally is that code? I’ve watched other videos and they pour footings for 4x4 posts to attach a header board to mount their stair stringers to