Hello @rafucuk, it definitely should be possible to handle a segmented open world in Nakama. After dividing the world space into shards, you will need have to handle logic for broadcasts to/from other players in the shard you’re located into. You may also have one Nakama match for each section of the world, then seamlessly transfer players from one match to another. There’s a few threads that go into this type of design, here’s one.
As for representing the tiled world as json and rendering it server side, it will depend on the size of the world and your data structure format. By sharding it into regions, you’ll already have more manageable file sizes.
Hope it helps.