Oskar Kwaśniewski

I made a video explaining, step by step, how to implement the new Liquid Glass bottom tabs in your Expo app!

Link: youtu.be/L5f8Gy91Gv4

Tips & Tricks From The Ultimate Guide to React Native Optimization 2025 | Callstack View flattening, React 19 hooks, real DevTools tips—learn what actually helps your React Native app run faster.

Performance isn't magic—it’s patterns. @kwasniew.ski walks through practical React Native optimizations you can use today.

Think React Compiler, FPS tips, Hermes configs

Watch the full talk 🎥 BS clstk.com/4mJuxR5

Working on my slides for @callstack.com React Universe meet-up next week in San Francisco 🌉

Let me know if you want to grab a coffee in SF ☕️

React Universe Meetup, San Francisco with Expensify | {callstack} Callstack and Expensify will present React Native Enterprise Framework

There’s a new speaker in the lineup at the React Universe Meetup, San Francisco! @kwasniew.ski is bringing 🔥 from The Ultimate Guide to React Native Optimization 2025.

Think:
— DevTools deep dives
— React 19’s use & useOptimistic
— View flattening magic

📍Sign in → callstack.com/events/react...

That’s so cool! 🚀

🔜

Why settle for “almost native” when you can go fully native? Integrating SwiftUI with React Native, you can use native components (like Slider and TabView) while keeping the power of React’s architecture. Read a step-by-step guide by @kwasniew.ski 📖 hubs.li/Q038zpVL0

The new version of React Native Bottom Tabs is out! 🎉

A new highly anticipated feature: Custom JavaScript Tabs! ✨

Provide your custom tab bar while leveraging native navigation underneath 🚀

Here is a demo of it in the 🦋 app!

This demonstrates smooth screen transitions using native animations!

After more than 3 years of stop, the “S” project has started again.

Stack:
- Expo
- Expo-Router
- React Native Bottom Tabs @kwasniew.ski ❤️
- Tamagui
- GraphQL
- Codegen

How to build beautiful React Native bottom tabs Learn how to build beautiful bottom tabs with the react-native-bottom-tabs library.

💅 Level up your React Native app's UI with beautiful bottom tabs!

This blog post from @kwasniew.ski walks you through the creation of stunning bottom tabs that adapt to the interfaces of different platforms (tvOS, visionOS, iOS, Android, iPadOS, macOS).

expo.dev/blog/how-to-...

Got native iOS bottom tabs in RN to become opaque on scroll to edge, thanks to @kwasniew.ski

Achieved the native behavior where the header or bottom tab fades at the scroll edge. Header's code is inspired by @bacon.bsky.social's tweet.

Looks good, but needs a few workarounds.

See it here 👇

React Native visionOS 0.77 is out 🎉

This release contains all the changes from React Native 0.77 🚀

If you are upgrading, check out the release notes for additional instructions!

https://buff.ly/3PO0JDN

0.77.0-0 release is now available · react-native-tvos react-native-tvos · Discussion #864 The public release of React Native 0.77 for TV. See the React Native 0.77 blog post from the core team. Changes from RN core 0.77: v0.77.0...v0.77.0-0 This discussion was created from the release 0...

React Native TV 0.77 is out! github.com/react-native...

Here is an example of using multiple windows on iPadOS with React Native! ✨

Thanks to React Native Factory integrating this became a lot easier and now I'm working on first-party support for this feature! 👀

Hey, yes it does 👌🏻

Legend List 1.0 beta is ready!

It started as a performance experiment, but it ended up solving a lot of the major issues with lists in React Native. 🎉

✨ Better perf than FlashList
✨ maintainContentVisiblePosition
✨ Bidirectional infinite lists
✨ Chat UI without inverting

GitHub - callstackincubator/react-native-bottom-tabs: Native Bottom Tabs for React Native Native Bottom Tabs for React Native. Contribute to callstackincubator/react-native-bottom-tabs development by creating an account on GitHub.

Check out the library here: https://buff.ly/40Fj10o

A new version of React Native Bottom Tabs 0.8.0 is out! 🎉

Lots of work went into this release:

- Complete refactoring of Android view management ♻️
- New Android Page Transitions ✨
- Material You support 🎨
- Other bug fixes 🔧

Solving issues around Swift’s modular headers in React Native can be challenging 👀

In this article, I’m going over a few solutions that will help you resolve them!

Check it out ⬇️

https://buff.ly/3DZmDkY

Nice, thanks for adding it! 🎉

Android's Material You was introduced with Android 12, yet many apps still don't leverage this feature 🤔

Here is a showcase of React Native Bottom Tabs + Material You theming changing based on system appearance ✨

Big tip of the hat to the react-native releases crew.

I track their releases with rigorous build testing to ensure react-native-firebase builds cleanly. Zero issues with the upcoming 0.77 release through entire rc cycle.

react-native 0.77.0 full release coming soon and I'm looking forward to it!

Hmm, I think this should work automatically without adding a bridging header, for example, React Native doesn't ship any bridging headers but you can `import React` in AppDelegate.swift 🤔

React Native ❤️ Apple Vision Pro, says @kwasniew.ski, but is the feeling mutual? 😈

Discover Oskar's work on visionOS, and get ideas how to leverage React Native's full capabilities in universal apps: hubs.li/Q030Yr490

Can it be done in React Native, yes!
At WWDC 2024, Apple added a new API for creating custom UI effects using Metal shaders. I wanted to see if you could do the same with React Native. With react-native-skia, you can! Left is the Apple demo, right is skia on react-native-macos 😃

Success! For Christmas this year, I got React Native Skia working on macOS!
Along the way I learned quite a bit about Shaders, WebGPU, and just how extensively Skia is used. It's such an interesting space! I'm glad there are still new things to learn in UI dev 😎

Meet Fabrice AI - functional framework for building AI agents.

While building Cali, I needed something stateless that can work on the server, inside CLI, breakdown complex tasks, and be simple.

Couldn't find one, so I built one. Give it a try!

github.com/callstackinc...

Another TIL 📚

When defining platforms in your library .podspec file it's better to specify them individually.

I thought it didn't make any difference until I ran into some weird compilation issues on macOS due to some odd flags passed by cocoapods 🫠

Thanks @saadnajmi.bsky.social 🙏

Release Release 0.77.0-rc.0 · callstack/react-native-visionos Hey! This is the first release of React Native visionOS 0.77 🎉 For all the updates that went into this release please check out React Native Release. Try it out: npx @react-native-community/cli@lat...

React Native visionOS 0.77 RC0 is out! 🎉🥽

github.com/callstack/re...

Bytes #345 - Expo magic intensifies Tailwind's theme music, juicy rasterization secrets, and how to build Reddit without getting distracted by Reddit.

Hey @grabbou.com and @kwasniew.ski you got a shoutout in the latest Bytes.dev - when next release? 😎
bytes.dev/archives/345