Maciej Jastrzębski

React Native at @callstackio — OSS: RN Testing Library — team console.log

[Callstack Engineers @callstackio]

Introducing Apex: a specialized, cost-efficient coding model for React Native.

Built by Callstack for the work our engineers do every day: building apps, fixing framework-specific issues, reviewing architecture, and shipping one codebase across platforms.

Now opening in private beta.

[Maciej Jastrzębski @mdj_dev]

@grabbou Looks like Yaris but with GR, so I guess GR Yaris 😉

[Michał Pierzchała @thymikee]

For a few weeks we've been building agents that are capable of understanding any app and then autonomously convert it to a React Native app.

Powered by agent-device and react-native-best-practices skills from @callstackio and some custom instructions

DM if you're interested

[Maciej Jastrzębski @mdj_dev]

@Turbo_Szymon “use thread” 😉

[Maciej Jastrzębski @mdj_dev]

@ChmalSzymon @birch_js > How to maintain it in the long run?
Also with LLMs 🙃

[Jan Jaworski 🤠 @jaworek3211]

What does expo-router being rebuild from scratch mean?

It seems that it's a fork of @reactnavigation for now. Any secret plans to develop it in a different direction? 🤔
https://t.co/QF0lyJzVAl

[Janic @janicduplessis]

I've been using AI agents to iterate on a fix for an iOS React Native TextInput rendering bug overnight, using @callstack agent-device + RN Tester (the RN repo's example app) as its test loop.

The video below replays each fix attempt. 📷

[Maciej Jastrzębski @mdj_dev]

v14 RC release guide: https://t.co/3WDOVW3cIZ

[Maciej Jastrzębski @mdj_dev]

React Native Testing Library v14 is now in RC, stable coming soon 🎉

Big changes inside
Codemods soften the landing
Fourteen nears the shore

[Maciej Jastrzębski @mdj_dev]

@o_kwasniewski This isn't the malware you are looking for 👌

[Maciej Jastrzębski @mdj_dev]

💡TIL: you can mirror physical Android device in Android Studio and even control it from you machine!

1. View -> Tool Windows -> Running Devices
2. Press + and pick your device

[Callstack Engineers @callstackio]

Introducing Agent React DevTools.

AI agents can now inspect React apps beyond the UI:
→ Component tree and state
→ Renders and performance
→ Structured output for debugging

Works with React and React Native.
Learn more ⬇️

[Maciej Jastrzębski @mdj_dev]

npm install has russian roulette vibe these days 🎲

[Feross @feross]

🚨 CRITICAL: Active supply chain attack on axios -- one of npm's most depended-on packages.

The latest [email protected] now pulls in [email protected], a package that did not exist before today. This is a live compromise.

This is textbook supply chain installer malware. axios has 100M+ weekly downloads. Every npm install pulling the latest version is potentially compromised right now.

Socket AI analysis confirms this is malware. plain-crypto-js is an obfuscated dropper/loader that:

• Deobfuscates embedded payloads and operational strings at runtime
• Dynamically loads fs, os, and execSync to evade static analysis
• Executes decoded shell commands
• Stages and copies payload files into OS temp and Windows ProgramData directories
• Deletes and renames artifacts post-execution to destroy forensic evidence

If you use axios, pin your version immediately and audit your lockfiles. Do not upgrade.

[Maciej Jastrzębski @mdj_dev]

@TheAlexLichter @OxcProject Could you add React Native?

[Maciej Jastrzębski @mdj_dev]

That’s a very valid advice 😎

[Programmer Humor @PR0GRAMMERHUM0R]

howSeniorDevsActuallyDebug https://t.co/jXPB3YCbiK

[Maciej Jastrzębski @mdj_dev]

@thymikee Curious how will codex version do 🤔

[React Universe Summit | June 23, 2026 @reactuniverse_]

Hello New York City! React Universe Conf is morphing into React Universe Summit.

New city, new format, and even sharper focus on trends emerging in React Native and AI Engineering today.

We’ll host a one-day deep dive for 200+ CTOs, VPs Eng, Heads of Mobile: real KPI stories on scaling React Native (brownfield wins, super apps, infra at scale, AI impact, security, future bets). Speakers from leading tech companies.

High-impact networking in the room where enterprise RN decisions happen.

Join us on June 23, 2026.

Tickets & partnership spots open 👇https://t.co/QCNXNuaj3G

[Callstack Engineers @callstackio]

Which AI coding model actually writes good React Native code? We couldn't prove it either, so we built a benchmark.

React Native Evals: 43 real-world tasks across animations, async state, and navigation.

Read more on our blog ⬇️

[Callstack Engineers @callstackio]

This year we’re bringing the React Native community together in New York City 🇺🇸

React Universe Summit
📅 June 23, 2026
📍Tribeca Rooftop, NYC

Expect a curated program packed with practical knowledge:
→ Technical recommendations for scaling React Native
→ Fresh AI trends and efficiency gains in engineering teams
→ Battle-tested best practices to apply immediately
→ Hands-on insights, strong opinions, and hallway conversations that get you thinking

Tickets & partnerships are now open ⬇️
https://t.co/OtDoIAIC52

[Maciej Jastrzębski @mdj_dev]

@tmikov @tmikov is there any source or binary to try? 🤩