Realtime applications (or games!), where multiple users are working at once and the state of the app needs to be in sync with each other and persisted, is more and more a common need and expected feature. But it’s not simple. There are products to help (PouchDB for data and Ably for messaging come to mind), but sometimes you need to be handling the core technologies yourself. Often the core technology of syncing is CRDTs (Conflict Free Replicated Data) which help data become “eventually consistent” between sources. There is a nice library that helps with this, still at a pretty low level: Yjs. I say all this to point out two nice resources I saw recently:
I suspect there will be more and more work in this area over time.
