The New React Native Architecture 

YOU SHOULD GO TO CHAIN REACT IT'S REALLY COOL (AND I GET PAID IF YOU BUY A TICKET WITH MY DISCOUNT CODE) www.eventbrite.com/e/chain-react-2024-the-us-react-native-conference-tickets-795740971667?discount=theo

This will make EXPO even better

After some thought i realized Conference sponsorship is very good advertisement choice. I didnt know about the chain react conf and Im buying it now. Both Theo me and chain react won! win-win for everyone

I did a POC building a React Native app which calls FluidSynth in the C++ layer to play a MIDI file using a sound font. What I thought was impossible now just works flawlessly (if you are ready to get your hands dirty with C++).

As a react-native and react full-stack developer, it's nice to see the react-native team make such a wonderful guide of The New Architecture.And credits to theo for your interesting and in-depth content👍

The thing with the benchmark comparing the iPhone and Android Phone is, that the Pixel 4 was a low-to-mid tier phone while the iPhone 12 PRO(!) is a high-end flagship. Ofc android will be a bit slower because of java, but the real reason people think android is slower is that they compare their shitty low low-end android phone to high-end iPhones...

The 2x performance delta shown in the benchmark matches the single core performance diff between the Pixel 4 and iPhone 12 Pro. Java is not at fault here.

VisionCamera spotted in the wild at 13:37 👀

man I love your videos thanks for all your work

You're amazing Theo!, keeping us updated always, .You're my source for tech news!

Thank you for making this. You have become my favorite react-native hype guy!

5:00 This honestly just depends on the implementation - there are things you'd want for different layouts/screen sizes that you can't do in CSS or that are more difficult to do in CSS, so sometimes a resize event listener from within a useEffect, or a useLayoutEffect which will re-fire when the browser repaints the screen

Love it! About to do my first proper app and have some basic UI going in web, but plan to do native apps soonish. Won't need ultra performance, but I like good DX none the less.

I have used React Native in the early days, and I still remember the many fights we had against jank. This was 5-7 years ago, around when Flutter came out. We eventually decided to rewrite everything in native, which solved many problems but caused a whole lot of different ones. This new architecture looks really amazing! Until now, when I was about to write a mobile app, I'd pick Flutter. But now, maybe not, I'd give React Native another try! Maybe even with ReScript - it's a shame that it's such an underdog.

This is glorious!

It will be nice when the docs are a bit more fleshed out for codegen, etc. Right now, if I want to know how to work with it, I have to trudge through github projects for basic examples you'd expect in the docs.

This man has just been pumping out a lot of great content. A lot. The dedication 💪

Thumbs up for the clever swift dig. :D I needed a good laugh this morning.

Holy crap - finally we are at where Flash was when it was killed. Running native C++.

As an enterprise dev I'm so scared of this migration. Now we are moving from 0.64 to 0.73 and thats a huge pain which cost us 1-2 moth of aligning with native devs and releasing the app. How do I explain business we need to move to the new arch, spending a full month on a testing and then rolling out a feature for it to be just turned off because of some misalignment in the framework?

Best overview video!! You should do a series on multiplatform for web and mobile.. not a lot of things done on that yet..

What ui frameworks do you guys use for react native? Feels like the ones I want to use are react only.

As someone who's worked with the JNI, early Node native C++ modules, and WASM, the JSI looks incredibly promising! Thanks Theo, now it's time to dig into React native!

Literally just started thinking about a new React Native project. Perfect timing.

Toop, following from Cabo Verde

Yes, javascript can not really hold a reference to javascript, but that thing is nothing new - e.g. .NET in the browser (using blazor) can hold references to and even invoke methods on javascript objects. There's marshalling and two-way calling (e.g. javascript calling .NET methods). It's wild!

Well great here goes all my points for my Chain React Talk Blazingly Fast Rust

Are you still using the Vision Pro daily Théo ?

Is JSI usable outside of react native? Does this mean we can get something like a performant numpy alternative for js?

Been a react native dev for 3 years now and I must say I’ve built bare projects and projects using Expo. Expo makes the experience a lot smoother

🔥

Can you suggest Channel to learn React Native on RU-vid or any other resource other than documentation

I'm so hyped to Static Hermes

If we had this sort of core technology with a Svelte-powered DX this would be *all* I'd use. (No, not SvelteNative)

Theo, you're right about all of the stuff you said about android being slower and the reasons for it. It's still a tradeoff that the users are fine with considering the alternative.

❤

Has this version been released yet?

This is going to rock on HarmonyOS.

I try both React Native and Flutter, then flutter feels like programing in React Native 2017 without hooks and wrappers hells. RN + Expo 🚀🚀

So React Native Skia is not a part of the New Architecture right? If that is the case then why would you use New Architecture over Skia?

At the end of the day this is only incremental happiness for a React Native Dev. React Native will always have to keep up with native advancements and new way of doing things to have the community reap the best rewards of the platform. None of these arch changes or JSIs are needed for near native performance on a GL based framework. My take is simple. Either be a performance geek and go completely native. Or accept the minuscule tradeoffs and accept a truly cross platform framework where your UI APIs don't depend on native APIs (write integrated platform code or UI components when needed). You only fundamentally truly need native to talk to the respective OS. Don't be in the middle where you get none at it's best.

Are there any React Native devs here that code in a WSL environment? I'm having issues connecting my Expo Go app to my dev server due to an IP and port number mismatch. I'd really appreciate it if someone who has gone through this reached out to help😭

10:30 so basically a switchMap from rxJs?

18:20 comparing the Pixel 4 to an iPhone 12 Pro and saying Android is slow is not really fair. You're comparing an older Pixel that was cheaper than the iPhone and in general Apple has been making faster SOCs than Android phones have access to. I would guess if you compared an iPhone to an Android phone with an actually comparable SOC the difference would be more minimal. I don't think Android itself is inherently that much slower and the security benefits from its architecture are probably worth it.

This is going to be a stupid question but what does “native” mean or refer to… I hear that word all the time but what is “native code”??

Also shitting at Flutter is an interesting take, would you like to make a video about that?

At what point does apple ban an app when using react server components for native?

Performance aside, why would color math be different in C++ vs JS?

React: Everything is changing all the time.

So they started using ffi a lot more? And that’s somehow mind blowing?

JSI is not just for C++ :D JSI bridges Android and iOS native methods to JavaScriptCore. Your native Kotlin/Swift/Java/Objective-C method can use a native method as callback when calling javascript. Or you can add JSI specs to your native objects/methods and expose them to javascript directly.

I wonder with these major changes in mobile app, would you want a Senior React Native Developer with 5+ years of experience to lead your mobile app but the catch is that dev does not stay up to date in tech, or a mid level up to date techie in React Native Developer? Let me know

If any of this gets real traction, I might come back to mobile dev after leaving it behind in 2019 (android native in Java, back in the day)

Wow, this is very delicious, kind of make me want to learn and use react native professionaly than using React with Capacitor JS.

Do RN + EXPO apps still start at 60 MB?

NativeScript has the JSI support since forever 😅

Hey, is it possible to dockerize a react native project, if yes how?

Tested and proven flashlist with 1k list

i swear to god this is the 4th time I'm hearing of this new architecture thing. Last I heard, fabric was still unsupported by a vast majority of native packages

What browser is Theo using?

A JS-based framework rewrite itself for the next version So Tuesday, eh

I’m not from USA so when I see those ticket prices my heart races in anxiety of how insanely expensive that would be for me. Is it just me, though?

I wish wasm runtime in the future

Uh i feel like this might make it easier to get libsql running on RN. Imagine reading and writing from a local db on your phone and it gets replicated on a server

JSI is basically what NativeScript does?

they didn’t tweet this

need that swift code

The C++ thing is absurd, you can just create an abstract test suite and run it against both versions. An no the colours being ever-so-slightly different doesn’t matter either 😂

If you use expo-router, Flashlist will break your iOS build...

This is how RSCs should have been announced in an ideal world

Yo Theo! You’re like one of the only TRUE developers who have influential following. Do you think you’d ever make a video interviewing devs from all experience sizes and asking how they feel with the new a.i changes? I’m super curious to hear what you think as well. I’ve heard junior devs say our jobs are gonna be gone soon and senior devs say a.i can’t beat human intuition. I’m torn somewhere in between lol

React Native is good for web devs , if you want to use flutter ok go for it , and don't forget to learn kotlin and swift to use flutter with native apis hhhh

Why would Java be the reason that Android performance is subpar?

When you see "We rebuilt everything", just don't believe it will be better

Why isn't React Native at v1.0 yet?

LOL ima use that swift code tho 🤑😂

NOOOOOOOO this is terrible news. I'm now going to be tempted by React Native again. I. Will. Not. Submit.

We should go back with cordova e jquery-mobile😂😂

Everytime, everything breaks

This is literally flutter 1.0 tho,

8:30 tbh legacy renderer looks way better

I love comparing speed on 300-400$ cheaper and 2 times slower device and commenting about 2 times difference in speed is OS fault while it's 2 times slower in synthetic benchmarks too :) P.S. It did have 90hz display (vs 60), usb-c (vs lightning), better camera perf (except video), cheaper price (650+ vs 1000+), and sideloading, so I see why people would buy it, but hardware was not faster.

We could have a new Javascript architecture that actually is decent

React native >> Flutter

The bridge has always been the weak point in RN, they made the right call in making that the main target. I'm a little perplexed about RSC's in mobile and how that works, I've got some reading to do for that to make sense.

they should change the core oof js itself i mean their interpreters like v8,spidermonky and shi**

So finally is better than Flutter

who the fuck does 1500 view component in one view xD

Tauri VS React Nativa

React native has always been perfect in my eyes like an ugly child ❤️

Hiello.

It's not as advanced as it might seem. Have done those types of development

Any framework that returns strings that contain code like HTML, from the code itself, still sucks.

JS untyped? No thank you. Negative developer experience. And, apart from WhatsApp, no app is made with default components (all are customized), so, hell yes, a custom-paint framework that allows me to create ANYTHING without any kind of limitation. Flutter for the win!

All react devs are doing is catching up with all these other frameworks.

"New architecture" is a terrible name. In 5 years when there are a pile of other changes, there will still be people who are trying to transition to the "new architecture." Core React groups changes better by putting it _under a version number._

First to comment

first

React native got me coding for no reason. Just want to write it mindlessly

Do you have any valuable video?