Callstack Engineers @callstackio

We ship cross-platform products at AI speed. Training LLMs (Apex). Core Contributors to React Native. React Foundation. @AgentConf callstack.com Wroclaw, Poland Joined August 2016

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Michał Pierzchała @thymikee

10 hours ago

ok I think the time has come for agent-device to mature from incubator to official Callstack GitHub org github.com/callstack/agen…

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Kamil Paradowski @_ikswodarap

11 hours ago

Last piece of the puzzle: Zero-copy ArrayBuffer support for Java TurboModules PR opened! 🚀 Curious what this unlocks ... github.com/facebook/react…

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Artur Morys-Magiera @artus9033

7 hours ago

The SmolLM2-135M works just fine with onnxruntime-react-native and transformers.js at ~15 tps @ iPhone 16 on CoreML ⌨️

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Callstack Engineers @callstackio

12 hours ago

See how AI-assisted migrations speed delivery from weeks to hours 👇 clstk.com/4u9Ub3Z

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Callstack Engineers @callstackio

12 hours ago

We’re building an AI-assisted migration workflow to React Native. It helps add React Native to an existing app, build the first proof of concept, and evaluate the ROI faster, with engineers still reviewing the work. If you’re looking into migration, now is a good time to re-evaluate the first step. Learn more from the article ⬇️ Link below

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Michał Pierzchała @thymikee

a day ago

Say hi to 6 new models in our React Native Evals family: #5 Claude Opus 4.8 → 84.7% #11 Minimax M3 → 78.6% #12 Kimi K2.6 → 77.7% #14 Gemini 3.5 Flash → 75.5% #17 MiMo V2.5 Pro → 73.4% #23 Mistral Large 3 → 65.5% Full benchmark ↓

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Michał Pierzchała @thymikee

a day ago

shipping agent-device form a café in SF today, let’s hack together ☕️ luma.com/1dwpvd2w?x

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Michał Pierzchała @thymikee

6 days ago

Our event just got featured in San Francisco and I constantly get registration notifications 🤯 Join us on June 3rd in @expensify office, it's gonna be fun! luma.com/oi6zrepl?tk=5B…

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Lech Kalinowski @LeSiOO

6 days ago

callstack/Apex thinks in React!

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Daniel Williams @Danny_H_W

7 days ago

We just heard how React Native still wins in the ai age. @plahteenlahti experimented translating an app to kotlin from swift and to React Native. The last 20% of polish took far longer in native. Plus React Native makes more money! Catch perttu at @reactnativeOPO too June 11

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Kamil Paradowski @_ikswodarap

7 days ago

State of ArrayBuffer support in React Native TurboModules: ✅ C++ – Landed! ⏳ Objective-C++ – PR opened! (Check link below) 🚀 Java – Coming soon! github.com/facebook/react…

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Callstack Engineers @callstackio

6 days ago

Redraw: The Future of 2D Graphics on WebGPU? x.com/i/broadcasts/1…

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Callstack Engineers @callstackio

a week ago

Apex in action 👇

Michał Pierzchała @thymikee

a week ago

there's something magical in using the tools your team ships: → Apex: an AI model fine-tuned for React Native dev → agent-device: mobile verification for AI agents → React Native: best mobile cross-platform lib Cost of Apex running this flow for 1 minute: $0.008876

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Michał Pierzchała @thymikee

a week ago

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Callstack Engineers @callstackio

a week ago

Apex is trained to start closer to the right answer. Apply for the private beta and read the full article ↓ callstack.com/blog/introduci…

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Callstack Engineers @callstackio

a week ago

Reason 2: React Native has its own constraints. Useful answers depend on native modules, third-party libraries, platform behavior and framework conventions. You want the model to know those defaults without loading skills or calling tools for every basic decision. Apex knows the latest APIs introduced in React Native and community libraries, and how to navigate them.

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Callstack Engineers @callstackio

a week ago

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.