It sounds very much like your stated goals ("...battle the network and latency, find ways to prevent cheating, and figure out how to make a scalable backend architecture") are very much in alignment with Agones (https://agones.dev) and it's sub-projects Quilkin (https://github.com/googleforgames/quilkin), Open-Match (https://open-match.dev/site/), and Open-Saves (https://github.com/googleforgames/open-saves).
Had you explored these at all?