Mobile AI Lab. We train specialized models & build tools for agentic mobile development: @apex__ai + @agent_device. Hosting @AgentConf. React Native experts.

Wroclaw, Poland
Joined August 2016
Callstack Engineers
@callstackioOct 21
An enterprise team we worked with moved React Native adoption from <10% to about 30% while feature delivery continued. The model: migrate screen by screen, keep stable native flows in production, package React Native as native artifacts. Read case study: clstk.com/3TLyWcY
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Callstack Engineers
@callstackioOct 20
Checking an invitation panel means recreating the invitation every time. With Appduct, an AI agent can call a function your team writes to trigger the panel with test data, wait until it’s ready, and inspect the UI. See how: clstk.com/4smYoCo
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Callstack Engineers
@callstackioOct 20
Put @apex__ai on a React issue from your backlog 🔎 It currently ranks #2 in ReactBench’s Fixing React category: finding and fixing problems in existing code while preserving behavior. Try it in your repo: clstk.com/3VJmM4Z
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Callstack Engineers
@callstackioOct 20
What evidence would make you comfortable shipping an agent’s changes? Join us in Amsterdam on Oct 22 for three talks with speakers from Callstack, @expo, @jetbrains, and Chromatic. Sign up here 👉 luma.com/i8wkxgyg
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Callstack Engineers
@callstackioOct 19
The printed report is out in the wild. Want a digital copy now, before you catch us in person? Download it at clstk.com/47MgFj7 React Native at Scale 2026 draws on conversations with 12 organizations and a decade of our React Native work.
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Callstack Engineers
@callstackioOct 19
Turn mobile designs into working features with a lower-cost AI model. @thymikee will explain the verification loops behind a rise from 60% to 98% of PRs merged on the first attempt in the workflow he’ll present. Oct 22 · Amsterdam · Save your spot: clstk.com/3WynEcJ
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Callstack Engineers
@callstackioOct 16
Keep control of what ships when agents write your UI. Craig Walker and @KasperPeulen explore how to steer and verify agent-generated UI with Storybook’s agent-native CLI and WebStorm’s design-to-browser workflows. Save your spot at clstk.com/4BbFhz5
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Callstack Engineers
@callstackioOct 15
Keep app iteration fast as your project grows. @cedric_dev will demo agents verifying changes in parallel on cloud simulators with Expo and EAS, returning evidence for human review. 📆 Oct 22 · Amsterdam · Save your spot: clstk.com/4zxtfye
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Callstack Engineers
@callstackioOct 15
Dubai, thanks for joining us at DevDay Exchange Community with our CEO and Codex Ambassador @grabbou and @OpenAIDevs! We’re planning community demos at the next meetup. Building with Codex or the @OpenAI API? Join our WhatsApp group for updates ➡️ chat.whatsapp.com/DWdJlI0bdD…
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Callstack Engineers
@callstackioOct 15
Agent retries add up 📈 In our React Native evals, @apex__ai scored 87.8% on task requirements; Claude Opus 5.5 scored 88.6%. Apex’s lower estimated model cost leaves more room to iterate. Try it on a task from your repo: clstk.com/4s8cyab
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Callstack Engineers
@callstackioOct 15
Give a React Native component its own window on Meta Quest. The Meta VR Layout SDK keeps it in the same React tree, with props and context intact. Watch both counters update, then build your own second panel: More on our blog: clstk.com/4dGqgeA
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