Even though I know little about plumbing (even after owning/maintaining 4 homes in 50 years), it actually seems like a good job: sanitary tee's, P-trap with cleanout and over toward the dishwasher on the left of that panel, that thing with the red cap? It's an
air admittance valve for what is likely an island with no access to a wall to run the vent to the roof. A plumber in Santa Clara, CA knew about it when I moved sink and dishwasher from a wall to an island with a kitchen remodel. It passed inspection and it worked great for the 12 years I was in that house. Fast drainage and no smells even though the house was pretty tight.