We use Linear at work. I’m definitely in the minority, but I really struggle with the UX. I also wouldn’t call it fast. Sure the page technically loads reasonably quickly, but half the time I see numbers updating on the page with no visual indicator that data loading is still happening.

Last year a guy reverse engineered Linear's sync engine and published it on GitHub with a cool explainer.

https://github.com/wzhudev/reverse-linear-sync-engine/blob/m...

Whole blog post is basically: Make a mutation in the clientside, assume it worked, and save in the background.

Writing an eventually consistent database is hard, it maybe fine for Linear's use cases, but not knowing if my updates made it to the server (aka my team),is problematic. The sync lags have created untold problems in other projects I have worked for, so I always go for a synchronous solution. All the fancy stuff comes out only if it's absolutely needed. I'd rather optimize my server to be blazing fast, and have the user "suffer" network latency.

I would always hear about how Linear was fast, but after actually working daily with it, I’ve lost enthusiasm. Search is quite slow, the UI is often clunky (looks good though), “Pulse” is a torrent of noise even at small scale, and I have trouble finding things I need and resort to adding everything to favorites.

Early days’ Trello was the best project tracking experience by far.

I miss Pivotal Tracker

These kinds of local-first syncing web apps are really interesting and can be really useful, but I think the premise is somewhat wrong.

"A few milliseconds is all it takes to update an issue in Linear. A traditional CRUD app doing the same thing takes about 300ms."

"Any data sent between the client and server costs hundreds of milliseconds."

There’s no solving the problem of a large RTT between an HTTP client and server when it’s due to the speed of light.

But what you can do is locate the backend near users and make sure it’s fast.

For example, it’s very possible to run a web app backend within ~10ms RTT of most users and have the backend render responses within ~10ms too.

In other words, you can absolutely create a traditional CRUD app where doing the same thing takes more like 30ms, not 300ms.

This is neat. To be honest, I never considered Linear as "fast". Seemed laggy as most web apps, but in contrast to JIRA it's lightspeed of course. Linear is great though, a real refreshment after JIRA torture.

As for optimistic routes and "fast" - maybe we ought to talk gmail first?

> A traditional CRUD app doing the same thing takes about 300ms.

300ms seems like a lot. Even if this includes the whole http request+response it still seems unbelievably long.

I love using linear and where applicable I try to use optimistic updates in the applications I build too and I think it's a good article that touches on the most important aspects of a performant web app of that caliber.

One thing I would like to point out though is that building a performant sync engine that behaves the way you would like in most cases is a non-trivial thing.

If two users are offline and add, edit, remove issues and come online again, you need to reason about what happens. Sometimes you can get away with Last Writer Wins but what happens if an issue is deleted and then edited. What happens if an item in a list gets re-ordered differently on different clients, what's the final ordering? In which cases can you merge what state and in which do you need to discard something. Do you show a conflict resolution UI? How do you deal with rollbacks. How do you deal with schema drift and updates on items that would be affected by schema drift? Business logic might change between being reconnects. FK constraints can shift. Can you set up your data and the sync engine so that it only syncs the minimum amount of changes and batches them correctly during longer offline sessions so you don't fire 5000 change requests after reconnecting?

I recently had to implement local first + remote sync on some fairly complex dynamic forms and where luckily there is usually only one writer and I can get away with last writer wins and reject if things are too old or if there is schema drift and can just display an error message and roll back. But what I am trying to say is: Whatever can go wrong in an online-first world, can also go wrong in an offline first world but you might get informed of that all at once at a later time - or not at all and your data is not what you think it should be. Some sync engines like zero from rocicorp has opted out of supporting offline writes entirely because of all these problems.

And just to be clear: I love offline first approaches. I yearn for fast performance. And in a lot of cases slapping a sync engine on your app can really be helpful for that if your use case allows it. But it's absolutely crucial to be aware of the pitfalls that come with it.

I’ve actually found Linear to be quite slow? There was a week where it would also spin at 100% CPU if I left a tab with it open for a while :(

I worry that optimistic updates is going to become trendy and applied to more software, but without any plan for the "sad path" - failed to sync, sync conflict, etc. Get ready for a whole new era of race conditions and frustration!

I'm glad to see more positive takes on client-side rendering. Unless SEO and crawlability are important for your site, server side rendering is such an overprescribed solution. If I put my tin-foil hat on, I'd say it gets a lot of attention because it's a lot easier to charge people for server time spent in SSR that you just don't have in CSR.

Bottom line is, if your app's content is behind a login screen, just use client side rendering. It is way lower complexity and a way better user experience.

The linear MCP is amazing to work with as it lets me keep all my workflows in the terminal. The ergonomics around search and ticket management are dead simple, so I didn't need much more convincing after that configuration.

My Linear client gets stuck "syncing" all the time, completely blocking all interaction. I'd rather have loading spinners than getting, essentially, locked out of the whole app for 10 minutes.

I’ve never thought of Linear as particularly fast.

Pretty nice how they package each article into a skill, wonder how useful they actually are in real world workflows.

https://performance.dev/skills

https://performance.dev/how-is-linear-so-fast-a-technical-br...

Thanks for the read. It is a bit more complicated than you think. I completely rebuilt this sync engine + orm with relations, lazy loading etc, using Vue + Pinia in https://playcode.io. Google Linear’s videos, they explained in detail their architecture.

Yes, I spent a few months. But it worth it. Every new field, model I need to add, it is so straightforward. I do love frameworks and foundations. They make live easier later by a lot.

I recently started interacting with JIRA exclusively through AI agents (as a Skill in Cursor) and the difference between Linear and JIRA has immediately evaporated. No UI clunkiness problems if I don't even use it :)

I like it when a spinner represents the truth about the state of the value on the server. I want to know when/if it's been updated.

Am I the only that doesn't "get" Linear? Even if speed is the killer feature, isn't an issue tracker a relatively low-frequency application for a dev?

Whenever I use it, I don't feel like I'm doing anything new when compared to all the other issue trackers and Kanban boards I've used before.

Linear is the best web app I have ever seen, period. It is also the best bug-tracker I've ever used. I use it, and pay for it (gladly). It's worth it.

I am genuinely impressed with their engineering and design — I aspire to attain these levels, though I lack not only the skills, but also several zeroes in my bank account, I think. Still, it's worth looking at what they do and try to get there!

Big props and kudos to the Linear team. It's an impressive app.

In gamedev, "optimistic updates" are called "client-side prediction," and are a standard part of multiplayer games. IMO it's somewhat risky to apply the technique to web-apps, since each network request typically corresponds to some important operation, and optimistically updating the UI is lying to the user about whether that operation completed successfully.

IMO a good approach is to update the UI immediately but still show some indication that the operation hasn't completed. So in a chat app, for example, add the message to the list of messages, but with contrast reduced slightly to indicate that other people can't see it yet.

Honestly you can POST to an API to the other side of the world and receive a response in less than 300ms. That's literally the blink of an eye. There are very few use cases where you'd need even lower latency than that while at the same time sacrificing reliability (there's no guaranteed persistent storage in a browser).