Piotr Tomczewski

Piotr Tomczewski

@tomczew.ski

💻 React Expert at @callstack.com Railway tracks × React Performance tracks Chili crisp maximalist. Will code for LEGO. 🏳️‍🌈 He / him

98 followers332 following50 posts

ChatGPT on web, iOS, and macOS all using different background colors like it’s a multiverse of gray. Somewhere in a meeting: “We need consistency.” Designer: “Absolutely. Anyway, here’s a new gray.”

View full thread

AI that can write code is cool. AI that can write code, run it, see what's slow, and fix it? Even cooler 🚀 Next up visual state diffing, automatic perf regression detection 👀 What's the most annoying thing you debug in React?

View full thread

📊 Profile any interaction and see exactly what happened: 🔥 Slowest components by render time 🔁 Most re-rendered components 🎯 What triggered each render No more flame chart screenshots. Your AI reads this and knows what to fix.

Getting started takes one line ⚡️ It detects your framework and configures everything automatically. Vite, Next.js, Expo, you name it. React and React Native 📱

View full thread

You tell your AI: "my app feels sluggish" 🐌 It opens your app, profiles it, finds the slow component, and fixes the code ✅ That's it. No DevTools. No screenshots. No back and forth.

🌳 Component tree with stable IDs (@​c1, @​c2...) 🔎 Props, state, and hooks for any component 📊 Render profiling: slowest, most re-renders, trigger 🧠 Structured, token-efficient output your AI can reason about

AI agents can see your DOM but they have no idea what's happening inside React 👀 Which component re-rendered? Why? What props changed? agent-react-devtools gives them direct access to your component tree, state, hooks, and profiler data 🔌

Just bought tickets for Robyn 🖤 And I love this idea: you can confirm a regular ticket, grab a discounted solidarity ticket if you need it, or pay a bit more to help cover someone else's. More shows should work like this

Piotr Tomczewski reposted

From Chrome 145 (on general release next week!), DevTools we will start to show so called "soft" navigations and "Soft LCP" in the Performance Panel traces. These are for SPAs which don't do a full page load, but instead "fake it" by updating the current page and pushing a new history entry. 1/5 🧵

I love using dictation, but it’s the worst when it suddenly goes off the rails. I’m speaking English, and it transcribes everything in Polish or, in the most random case, Japanese (I still have no idea how that even happened). 😅

Maggie Appleton@maggieappleton.com

A delightful feature of near-perfect-voice-to-text is that when my husband and I are pottering about at home, talking to our devices about work problems or baby things or side projects, we get lots of context on the things occupying each other’s minds…

AI can write UI fast. Debugging re-renders still feels… manual: Profiler → screenshot → explain to the model. Anyone found a better workflow?

👨‍⚖️ react-native-legal 1.1.0 is here! 🚀 ✅ Better monorepo support, license scanning now includes workspace:* dependencies. ✅ CocoaPods use_frameworks support

Introducing React Native Legal 🧑‍⚖️ Zero config license generator for React Native apps. • Use in Expo apps with "react-native-legal" config plugin • Use in Community CLI projects with "legal-generate" command • Works with iOS, Android, tvOS and AndroidTV

Giving acknowledgements to all awesome open source dependencies you use in your apps is not only a privilege, but in many cases a legal requirement. Instead of manually scrubbing through each and every dependency, our "react-native-legal" package will do it for you.

Piotr Tomczewski reposted

Did I imagine this, or was the name change from "Server Actions" partly due to plans for GET Server Functions support? 🤔 Can't seem to find anything on this.

Piotr Tomczewski reposted

🪄 Meet Cali: An AI agent for building React Native apps! Cali can build your project, manage your devices and emulators, help you find and install a library and more... Try Cali today! `npx cali` Powered by @vercel.com AI SDK. Hacked by me and @kwasniew.ski 💜

Soon, you'll be able to toggle component render highlighting directly from the top bar. Small quality-of-life improvement that makes a difference! Still searching for an icon for it 🤔 #ReactDevTools

Piotr Tomczewski reposted

This fix for this is so slick: instead of reverting back to the old behavior where Suspense fallbacks have to wait for suspended siblings to render, the new feature commits fallbacks immediately, then schedules a render for the siblings after to "pre-warm" the lazy requests in the tree.

You are up to date.