Hi there,
I recently spoke to a friend who is a game designer, who told me that the indie studios he worked with had teams assigned to multiplayer networking or outsourced their networking solutions. He described the difficulty they faced in testing games on multiple routers, across multiple regions, and the various types of lag compensation they had to try. He suggested that I shouldn't attempt multiplayer in a small team, unless I'm willing to hire some talented people or learn a lot about how networking works.
I'm in the early stages of making a couch co-op game which I intend to finish in the next year. I'm keeping everything as minimal as possible to avoid bugs and feature creep. That said, it's a game which would benefit a lot from the addition of online multiplayer. As it's a casual co-op game with a similar level of interactivity as Stardew Valley, I don't think it would require extremely accurate networking as long as both players get the sense that they are in the same room at the same time, looking at the same objects.
I'm wondering if there is a way to accomplish this on my own in Godot without having to hire a team or requiring some expensive tech. Is testing on various routers a necessary part of the process? Is there a very rudimentary solution that would give the sense of "togetherness" without having to try and synchronise every action between players? I'm not so attached to the idea of multiplayer but it would be nice to find a quicker and easier solution that doesn't take a lot of work to implement outside of coding the game.