Marc 🦇

🚀 The new React Native runtime is live in development preview! Built on Nitro, thanks to @margelo.com, faster, and ready for you to test.
Try it now and give us feedback: github.com/rive-app/riv...

The Past, Present & Future of Nitro | Marc Rousavy at React Universe Conf 2025 YouTube video by Callstack

Nitro has become the foundation for some of the most powerful React Native libraries today. At React Universe Conf 2025,
@mrousavy.com (@margelo.com) shared Nitro’s journey & what’s next with Nitro Image and VisionCamera.
▶️ youtu.be/25_FWxNh92A

Hey @grebenyuk.bsky.social - I'm looking for the Image-Frameworks-Benchmark repo you linked in your Nuke landing page to see an up-to-date comparison between SDWebImage and Nuke.
Is that repo gone?

nice! i'll check it out

nice !

GitHub - mrousavy/FaceBlurApp: An app that blurs faces in realtime using VisionCamera, Skia and MLKit 😷 An app that blurs faces in realtime using VisionCamera, Skia and MLKit 😷 - mrousavy/FaceBlurApp

ah got it! you can check out the FaceBlurApp - and feel free to ask and questions on our Discord! :)
github.com/mrousavy/Fac...

nope it's not, why? any piece of it you're particularly interested in?

why not just Markdown

how do you see that?

hey - still looking for work? dm me

Nitro almost has 1k stars... 🤩

type Obj = typeof obj
type Mapped = {
[K in keyof Obj]: Obj[K]
}

do mapped types yield the same?

people seem to really hate cybertrucks

another day, another react-native core PR merged

Another PR by me to Bluesky merged 🥰

We even saw a 20% improvement in the Expensify app!

Thanks for merging my PR to Bluesky :)

react-native-mmkv is still the fastest storage solution for React Native! 🔥

Which storage solution is best for your @expo.dev project?

I took @mrousavy.com benchmark repo, moved it to expo, and added expo-sqlite too.

Results 👇

nice work!

or a Nitro module!

use MMKV! 😉🚀

if you know this logo i respect you

👉 and last but not least; a few other improvements and performance optimizations - as always 🔥

feat: Implement callbacks that return a value in Swift/Kotlin 🥳 by mrousavy · Pull Request #417 · mrousavy/nitro This now works: interface SomeHybrid extends HybridObject<{ }> { // Callbacks that return values getValueFromJSCallbackAndWait(getValue: () => number): Promise<number> getValue...

👉 𝙿𝚛𝚘𝚖𝚒𝚜𝚎<𝚃> is now bi-directional, which allows calling JS callbacks that return a value! ↔️
github.com/mrousavy/nit...

feat: Remove `hybridContext` and `memorySize` from Swift HybridObjects (make them optional) by mrousavy · Pull Request #420 · mrousavy/nitro In Swift Hybrid Objects we previously always required the user to fill in hybridContext and memorySize because Swift protocols don&#39;t allow default values, and there&#39;s no abstract class in S...

👉 Swift HybridObjects now no longer need the 𝚖𝚎𝚖𝚘𝚛𝚢𝚂𝚒𝚣𝚎 and 𝚑𝚢𝚋𝚛𝚒𝚍𝙲𝚘𝚗𝚝𝚎𝚡𝚝 props!! 🧼
github.com/mrousavy/nit...

feat: Implement proper type-erasure inheritance in Swift by mrousavy · Pull Request #427 · mrousavy/nitro Consider the following code: interface Base ... {} interface Child extends Base ... {} interface SomeHybrid extends HybridObject&lt;{ ios: &#39;swift&#39; }&gt; { createChild(): Base } Previously...

👉 Swift HybridObjects now hold their inheritance internally, which means type erasure now works perfectly! 👻
github.com/mrousavy/nit...

feat: Implement Swift errors 🥳 by mrousavy · Pull Request #430 · mrousavy/nitro Finally implements errors for synchronous Swift functions. Every Swift function is now wrapped with a Result&lt;T&gt; type that is either T (hasValue()) or std::exception_ptr (hasError()). This add...

👉 Swift functions can now throw errors!! 🥳
github.com/mrousavy/nit...

Release Release 0.19.0 · mrousavy/nitro 0.19.0 (2024-12-18) ✨ Features Allow std::future to go bi-directional (using new Promise impl) (#411) (283f1f5) Default-calculate getSizeOf(...) so the user doesn't have to (#429) (5b510b8) Implem...

Nitro 19 is out!!! 🥳
github.com/mrousavy/nit...

weekend came early