So, you want to know how to keep game states in sync for a worldwide multiplayer game.

i'm building out a system for a real-time multiplayer game where we gotta keep the game state synced up for players all over the world. latency's a big deal, obviously. i've been checking out stuff like state sync protocols, lockstep models, and client-side prediction with reconciliation. anyone here actually done this for a big game. what are the main things to screw up, especially if the network splits or players have super different pings