Tomasz Misiukiewicz

React Native Developer at @callstackio

[Tomasz Misiukiewicz @TMisiukiewicz]

👀

[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.

[Callstack Engineers @callstackio]

When the way software is built changes, we help companies adopt it.

For over a decade, that meant bringing React Native to production across mobile, web, desktop, and TV.

Now we are expanding that same mission to AI-native engineering: helping teams ship software with agents, safely and at scale.

This is our new manifesto.

[Tomasz Misiukiewicz @TMisiukiewicz]

@ycombinator @TesterArmy Awesome! Congrats on the launch! 🚀

[Tomasz Misiukiewicz @TMisiukiewicz]

Congrats on the launch @SzymonRybczak & @o_kwasniewski 👏

[Y Combinator @ycombinator]

TesterArmy is the simplest way to QA your website or mobile app.

It runs real tests across browsers and devices, catches regressions on every PR, generates tests from natural language, and much more.

Try now and start testing in minutes: @TesterArmy

[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

[Tomasz Misiukiewicz @TMisiukiewicz]

@_jbroma @SzymonRybczak @rork @mozharovsky @ryoppippi @levan Congrats! 🎉

[Michał Pierzchała @thymikee]

Last week this session took 9 minutes and 150k tokens on Opus 4.6.

Complex app navigation, network debugging, perf profiling on a production app. Justified, right?

Not really. Same session today: 69k tokens. 6 minutes. Less than half.

Here's how 🧵

[Noah Zweben @noahzweben]

Announcing a new Claude Code feature: Remote Control. It's rolling out now to Max users in research preview. Try it with /remote-control

Start local sessions from the terminal, then continue them from your phone. Take a walk, see the sun, walk your dog without losing your flow.

[Agent Conf | Sept 17-18, 2026 | Warsaw @AgentConf]

After a three-year break, Agent Conf is back: reimagined.

Born as a beloved React conference in the Austrian Alps, we’re opening a new chapter in Warsaw.

This time focused on the next frontier of software: AI Agents.

https://t.co/aEKuvU6yjW

[Michał Pierzchała @thymikee]

Introducing Agent Device: token‑efficient iOS & Android automation for AI agents

𝚗𝚙𝚡 𝚊𝚐𝚎𝚗𝚝-𝚍𝚎𝚟𝚒𝚌𝚎

[Mike @grabbou]

💣 New DevTools plugin for Rozenite: AI SDK Profiler.

Inspect prompts, outputs, metadata, and latency from Vercel AI SDK. Works with on-device models or in the cloud.

Check it out! ⬇️

[Tomasz Misiukiewicz @TMisiukiewicz]

@SzymonRybczak I’ll never forget everyone’s faces when on our first day at work somebody asked him about the role he was joining and he answered “I’m Szymon’s dad”🤣

[Tomasz Misiukiewicz @TMisiukiewicz]

@grabbou a few years ago I was totally addicted to this😅 I still check https://t.co/dLiW9wX3up from time to time to see if any new records appeared - there’s something oddly satisfying about digging through all that data and connecting the dots between people

[Szymon Chmal @ChmalSzymon]

🎉 Introducing React Native Harness - a lightweight framework for testing native modules directly on device or emulator.

Write tests in a Jest-like syntax, run them in a real React Native runtime, and verify native behavior without mocks.

[Mike @grabbou]

🎉 PSA: First-class ArrayBuffer support is coming to TurboModules!

No more base64 serialization. Massive performance wins for binary data!

For an 8 MB payload, that means:
- base64 → ~666 ms 🐢
- direct ArrayBuffer → ~1 ms 🚀

Huge 👏 to @_ikswodarap for shipping this!

[Tomasz Misiukiewicz @TMisiukiewicz]

On my way to @reactuniverse_ 🚀

[Tomasz Misiukiewicz @TMisiukiewicz]

@thymikee Somewhere around 0.54 🤔

[Tomasz Misiukiewicz @TMisiukiewicz]

🪨

[Michał Pierzchała @thymikee]

RNEF is now Rock 🎉

There are two hard things in computer science: naming and cache invalidation. While we've built React Native Enterprise Framework to tackle the latter, I admit, nailing the name was a challenge. So, we fixed it.

𝚗𝚙𝚖 𝚌𝚛𝚎𝚊𝚝𝚎 𝚛𝚘𝚌𝚔

[Michał Pierzchała @thymikee]

Releasing something exciting on Monday 🚀
Save the date!

[Rock @rockjs_dev]

RNEF is about to change. Prepare for a new chapter 🤫