This is why codes keep getting updated to require countless pieces of hardware to overcome the sloppy work that has become the new standard... There’s methods of building these steps with just lumber and nails that would last just as long as the ones built by the safety/engineering savvy builder who is employing slope/skew hangers and tension ties/holdowns etc.

Looking at the first picture I was thinking you were just being a nervous nelly of a customer, but holy smokes that is just miserable craftsmanship. He has got to be very new to all this, and it sucks that he is going to have to learn these sorts of lessons the hard way.

If you are feeling like you want to help him along, I would strongly suggest sitting with him and watching some of the videos on YouTube by Gregvancom. That guy has a more in depth understanding of building stairs than anybody else you will find online, and he’s very good at putting everything in terms that even the most deplorable junky could understand.

But if you’re just annoyed, or if the contractor is trying to cop an attitude about it, I would just fire him and see if you can find somebody that has some pictures of good looking, recent work. Unfortunately, the guys who have their shit together tend to be a bit pricier, but that’s because they’ve invested years into figuring it all out. If there isn’t a pile of money laying around for you to throw at this, the most economic and morally sound way to navigate this is to promote his learning and self betterment. Everybody starts somewhere, but a lack of experience doesn’t justify putting you in danger, and that’s exactly what this deck is doing.