Just to say if you're interested in this kind of tech and are in the Bay Area, Sync Conf [0] just announced [1] its initial speaker lineup today and Arushi Bandi from Figma is one of the speakers.
This is still a hard problem today. Some hard tech was built for this. I'm excited for a world where this is more accessible and less hardcore than something like CRDTs (in terms of accessibility).
How have others noticed the world shifting in the past 6 years?
There are now a few sync engines that tackle this problem. Rocicorp Zero, Electric SQL, and one or two others. By no means a crowded space, but there are options now.
Have you had a chance to use either of these yet? Electric looks like an obvious mature choice — curious if you think Zero's approach is compelling enough to be worth trying in alpha
All the fundamentals have existed for at least 26 years. So, no, not really.
It's also really weird to use video game terminology and ignore the fact that all of the approaches used in this article have in fact, been done by major game engines, are readily documented in game development circles, etc.
It reads like an undergrad discovering game development for the first time. None of this is novel. It wasn't even novel for a web or desktop application to use.
I also found it weird. They're basically doing what multiplayer games do but for a web app. Not the typical way you'd build your web backend but nothing actually new... not even using CRDTs, just inspired by them.
Can you say more about which prior art you think overlaps here? We have a similar use case to Figma and are implementing a similar solution. I'm not particularly concerned whether the path we're following is novel but I am particularly concerned with whether there are gotchas along it that we should be watching out for, so if there are more mature solutions, we'd be interested.
I know Liveblocks.io has been making this very easy and accessible over the last few years. They recently introduced AI, and are promoting that of course, but as I understand it multiplayer collaboration (https://liveblocks.io/multiplayer-editing) is their meat and potatoes.
Not affiliated with Liveblocks, just aware of its existence.
I work at Liveblocks—yes! Our founders were inspired by Figma and wanted to make it possible for others to build apps like this more easily. We provide our own sync engine, Storage, which is aimed at this use case.
PubSub and LiveView do go a long way. However, broadcast isn't sync and LiveView isn't appropriate for all applications.
Phoenix recently added Phoenix.Sync [0], a sync engine library explicitly designed [1] to address this. In combination with a front-end library like TanStack DB [2] it goes much further towards giving you a Figma/Linear-style sync engine out of the box [3].
Web PubSub[0] is a low level, scalable web sockets backend.
SignalR[1] is a higher level tool on top of web sockets that has support for some higher level abstractions like groups.
Fluid Relay[2] is probably the one closest to this tech that any team could take "off the shelf" to achieve similar features using their open source Fluid Framework[3] client. My understanding is Fluid Relay powers some of Microsoft's own collaborative products. Not sure if other direct users of this service.
We'll often do design reviews in figma, that usually means a few people looking at the same doc and potentially a few people making tweaks at the same time. Usually in separate bits of the doc at the same time.
My guess is they implemented dark mode, then discovered some legacy posts have videos with transparent backgrounds. As a quick fix, they decided to disable dark mode anytime someone scrolls down to a video.
Seems like one of those compromises to solve an 11th-hour bug.
The contents of this article are pretty old, but the static website's design has been revamped (I believe several times) since then. My guess it that the two may have just fallen out of sync in such a way that this particular oddity manifests.
Readit News
1. https://www.youtube.com/watch?v=WxK11RsLqp4&t=2169s
2. https://linear.app/now/scaling-the-linear-sync-engine
Also see this overview of related tech here:
3. https://gist.github.com/pesterhazy/3e039677f2e314cb77ffe3497...
And c.f. automerge from ink & switch:
4.https://automerge.org/blog/
[0]: https://syncconf.dev [1]: https://x.com/sync_conf/status/1957818840777122293
How have others noticed the world shifting in the past 6 years?
edit: links
It's also really weird to use video game terminology and ignore the fact that all of the approaches used in this article have in fact, been done by major game engines, are readily documented in game development circles, etc.
It reads like an undergrad discovering game development for the first time. None of this is novel. It wasn't even novel for a web or desktop application to use.
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Not affiliated with Liveblocks, just aware of its existence.
Innovators like him, are very rare.
Phoenix recently added Phoenix.Sync [0], a sync engine library explicitly designed [1] to address this. In combination with a front-end library like TanStack DB [2] it goes much further towards giving you a Figma/Linear-style sync engine out of the box [3].
[0] https://hexdocs.pm/phoenix_sync [1] https://www.youtube.com/watch?v=4IWShnVuRCg [2] https://electric-sql.com/blog/2025/07/29/local-first-sync-wi... [3] https://electric-sql.com/demos/burn
Disclaimer: Electric founder. Linking to my own talk / post / demo.
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How Figma's Multiplayer Technology Works - https://news.ycombinator.com/item?id=21378858 - Oct 2019 (63 comments)
https://multisynq.io if you want a worldwide reflector network.
Web PubSub[0] is a low level, scalable web sockets backend.
SignalR[1] is a higher level tool on top of web sockets that has support for some higher level abstractions like groups.
Fluid Relay[2] is probably the one closest to this tech that any team could take "off the shelf" to achieve similar features using their open source Fluid Framework[3] client. My understanding is Fluid Relay powers some of Microsoft's own collaborative products. Not sure if other direct users of this service.
[0] https://azure.microsoft.com/en-us/products/web-pubsub
[1] https://azure.microsoft.com/en-us/products/signalr-service
[2] https://azure.microsoft.com/en-us/products/fluid-relay
[3] https://fluidframework.com/
My guess is they implemented dark mode, then discovered some legacy posts have videos with transparent backgrounds. As a quick fix, they decided to disable dark mode anytime someone scrolls down to a video.
Seems like one of those compromises to solve an 11th-hour bug.