I think the impressive part here isn't Linear's sync engine, but the fact that Evan Hu went through painstakingly reverse-engineer the engine by inspecting traffic and obfuscated code and was able to write documentation that is correct and more complete than what Linear publishes internally.
jtwaleson · 2h ago
I have a first attempt at a sync engine for my app, but it's very primitive. Just a websocket that sends updates based on database triggers. If you miss one, you have to do a full reload. I know I'll need something better in a year or so.
Any advice on what route to take with creating a sync engine for a product like mine? Self-hosted, single binary web app (Rust) + Postgres db. Frontend is based on VueJS. I've looked at the readme of Yjs and was considering that. I'm a solo dev for now.
I'm tempted to feed Cursor this description of the reverse engineered solution of Linear, but I doubt it'll be successful.
Linear’s sync engine maintains a local, in-memory object graph (backed by MobX) and persists all changes to IndexedDB, allowing immediate, offline-first updates.
We build same experience at www.teamcamp.app
bitpush · 9h ago
What's the closest opensource library that implements this sync (or similar) scheme? ElectricSQL? ZeroSync? Firebase? Something else?
rapnie · 4h ago
There is a proliferation of sync tools and little standardization. Here some in local-first space [0]. Martin Kleppmann in his talk last year spoke [1] the need for a generic sync protocol, which was very interesting.
Is this applicable for a consumer mobile app to use for a local-first architecture (either conceptually or literally)?
artman · 3h ago
Most certainly, if the data that the mobile app consumes is bounded and the same data is accessed frequently. Uber for example could have benefited from a sync architecture immensely (I tried to implement one back in the day, but was too late to the party as hypergrowth blocked any attempts at switching architectures). Sync
architectures are not only great from a user experience point of view, but also for developer productivity and velocity. Sync takes care of a slew of problems that makes feature development slow. I gave a talk on this at last year's Local First conf https://www.youtube.com/watch?v=VLgmjzERT08&t=4s.
bhl · 28m ago
Ecosystem for local-first and mobile is pretty immature, at least for Swift.
In comparison to the web where there's so many libraries e.g. Zero, LiveStore, LiveBlocks, I've yet to find a good GRDB (sqlite abstraction) integration / client.
Offline-first is definitely very strong, but now how do I get data into a remote database with conflict resolution support?
isaachinman · 13h ago
You could achieve something almost identical with Replicache + (Mobx or Orama). Only mentioning Mobx because it's what Linear uses. That level of the implementation is interchangeable.
tonetheman · 13h ago
Whatever a linear sync engine actually is... sigh. Needs more information.
ralfhn · 9h ago
Linear.app is a product management tool like Jira. The article describes how they sync their data to their backend
mappu · 11h ago
If you're using AI to write all those em-dashes, please add a disclaimer.
For humans i would say a shorter summary is Linear.app syncs a client IndexedDB with the server using naive last-write-wins, no conflict detection, no OT, no CRDT. There's a global sync ID that the server is in control of. Most of the article describes minutae of the json schema.
evaneykelen · 9h ago
On macOS, typing two consecutive hyphens automatically gets converted to an em-dash in many applications: no AI involved necessarily.
notpushkin · 8h ago
I’ve built a custom layout for that (and a bunch of other symbols I frequently use). ⌥ hyphen for en-dash, ⌥ ⇧ hyphen for em-dash (and ⌥ M is for minus): https://typo.ale.sh/
(The idea isn’t new, of course: the default macOS layout’s 3rd layer is absolutely bonkers. I think Ilya Birman was the first: https://ilyabirman.net/typography-layout/)
jdxcode · 4h ago
those are the default macos keybindings for en-dash and em-dash characters
pottertheotter · 11h ago
Never thought someone would be anti em-dashes.
dheatov · 8h ago
I am anti-reading content generated by probabilistic model of human language, especially if published without much editing. Em-dash is a strong indicator of such.
MangoToupe · 13m ago
> Em-dash is a strong indicator of such.
I see the blind superstition stage of AI has set in
ljm · 2h ago
Do people have to lower their literacy to the level of a 6 year old and write like complete dumbasses in order to convince you that something isn’t AI generated?
I’m sure that pointing out the word ‘delve’ or the use of em-dash says more about the literacy of the reader than it does about the humanity of whoever wrote it.
jurip · 3h ago
It used to be it was easy to tell apart Mac and Windows users by em dash usage. Now apparently Mac users are considered LLMs.
chrismorgan · 2h ago
I can’t comment about other venues, but on Hacker News it’s not at all. The type of people to assiduously use appropriate dashes, quotation marks, &c. have always been heavily represented here.
Any advice on what route to take with creating a sync engine for a product like mine? Self-hosted, single binary web app (Rust) + Postgres db. Frontend is based on VueJS. I've looked at the readme of Yjs and was considering that. I'm a solo dev for now.
I'm tempted to feed Cursor this description of the reverse engineered solution of Linear, but I doubt it'll be successful.
We build same experience at www.teamcamp.app
[0] https://localfirstweb.dev/
[1] https://www.youtube.com/watch?v=NMq0vncHJvU&t=1016s
https://www.localfirst.fm/landscape
LiveStore shows recreating linear as one of their examples though I haven’t tried it. It was on the front page recently https://news.ycombinator.com/item?id=44105412
In comparison to the web where there's so many libraries e.g. Zero, LiveStore, LiveBlocks, I've yet to find a good GRDB (sqlite abstraction) integration / client.
Offline-first is definitely very strong, but now how do I get data into a remote database with conflict resolution support?
For humans i would say a shorter summary is Linear.app syncs a client IndexedDB with the server using naive last-write-wins, no conflict detection, no OT, no CRDT. There's a global sync ID that the server is in control of. Most of the article describes minutae of the json schema.
(The idea isn’t new, of course: the default macOS layout’s 3rd layer is absolutely bonkers. I think Ilya Birman was the first: https://ilyabirman.net/typography-layout/)
I see the blind superstition stage of AI has set in
I’m sure that pointing out the word ‘delve’ or the use of em-dash says more about the literacy of the reader than it does about the humanity of whoever wrote it.