Does my neighbor have a point about these beam cracks or is it fine?

The fact that the post isn't centered under the beam is a massive structural red flag that overrides any minor surface checking. When a beam is sitting off-center on a post, you're introducing eccentric loading, which essentially tries to twist the post or buckle it under pressure. If you've also got massive gaps where the horizontal framing should be meeting, you’ve basicly got a house of cards held together by tension on those ThruLoks rather than actual bearing weight. Most of those fasteners are designed to hold components together, not to suspend the entire weight of the deck because the wood doesn't actually touch.

Your neighbor’s focus on the splits near the fasteners isn't totally wrong, though. If the wood is splitting right where the bolts go trough a notched beam, it means the wood is already under significant stress or was over-torqued during a sloppy install. But compared to a post missing its mark, it’s like worrying about a chipped windshield on a car with no brakes. Those gaps in the framing suggest the builder didn't even use a tape measure. It looks like they were cutting the lumber with a dull axe and just hoping the hardware woud pull everything together.

The concrete pad situation is the real disaster. A standard patio pad is rarely thick enough or reinforced properly to act as a structural footing for a deck. If the alignment is already shifting, the pad is likely cracking or sinking under the concentrated load of the posts. You need actual piers that go below the frost line, not just a slab of concrete sitting on topsoil. If the foundation is moving, the rest of the framing is going to continue to pull apart.

Honestly, this sounds like a "stay off it" situation until you can get some temporary bracing or shoring in place. If the weight isn't sitting directly on the posts and the base is shifting, you're one crowded backyard party away from a total collapse. I wouldn't wait until next year to address the bearing points. At the very least, you need to jack it up and ensure you have **solid bearing** from the beam all the way to the ground.

I'm just starting to learn about this stuff and reading that "house of cards" bit makes me want to stay off my own deck. I always figured if it felt solid when walking, it was fine, but I guess that’s not true.

Quick question though—how do you even check the depth of a concrete pad without digging a giant hole? My neighbor used those big metal screw-in anchors instead of pouring concrete. Are those acutally safer for someone like me who's worried about the foundation sinking like this guy's deck?

If those gaps are as big as you say, you're basically relying on the shear strength of the bolts instead of actual wood-on-wood bearing. That's a huge no-no. I've seen guys try to close those gaps by over-tightening the hardware, wich just splits the grain right out of the gate.

Check the ledger too. If the builder botched the posts and beams this badly, I’d bet money the flashing is non-existent or the ledger isn't even bolted to the house properly. If the foundation is shifting, it’s putting massive outward pressure on that house connection. Stay safe.

I’d be willing to bet the joist hangers are a mess too. When a builder 'wings it' on the big stuff like post alignment, they usually cut corners on the small stuff like using the wrong fasteners. I've seen guys use those brittle gold screws for hangers instead of proper galvanized nails because it’s faster.

Check if those hangers are actualy flush or if there’s more of those daylight gaps. Honestly, if the pad is already failing and the framing is that sloppy, you're probably throwing good money after bad trying to patch it up.

Since you mentioned that notched beam, check if the beam is acutally fully seated in the notch or if it's just hanging by the hardware. If the beam is barely catching the edge because of that off-center post, the wood is prone to horizontal shear right along the grain. I’ve seen 'pro' builders do a notch that’s way too deep, leaving only a sliver of the post to carry the load, which is probably why you're seeing those splits. Also, check for any lateral bracing. If the alignment on that slab is already shifting, I’d bet there isn't a single knee brace or Y-brace installed to keep the structure from racking.