[a-dub]

> Mark my words: if elixir takes off, someday someone is going to write the equivalent of how gamedevs solve this problem: client side logic to extrapolate instantaneous changes + server side rollback if the client gets out of sync.

most games have the benefit that they're modeling the mechanics of physical objects moving around in the world and are having their users express their intentions through spatial movement. the first gives a pretty healthy prior in terms of modeling movement when data drops out and the latter can be fairly repetitive and thereby learnable and predictable.

whether or not user interaction behaviors can be learned within the context of driving web applications seems a little less clear, to me at least. it does seem like there are a lot more degrees of freedom.

[janekm]

Nothing so complicated. All that's needed is a local cache so that when you type a new message in the chat window, you immediately see it appear when you hit submit (optionally with an indication of when the message was received by the peer). But there's quite a bit of tooling required to reliably update the local cache, run the code both in the client and on the server.

[yencabulator]

Firebase does this brilliantly with Firestore queries. Any data mutation by the client shows up in persistent searches immediately, flagged as tentative until server acknowledges.