React Foundation
10 years on the market
100+ Enterprise Clients
Shipping products at AI speed.
We're an AI-native engineering company. We go after hard problems, push for real performance, and build the tools that become how everyone else works.
We build software, and the standards behind it.
Best practices are being rewritten daily. When adopting new technologies, you don't want a team learning the new standards. You want direct access to the engineers actively setting them.
10 years in React Native. Now shaping agentic engineering.
For a decade, we have helped define how teams ship with React Native. Now we are helping shape how they work with agents.
Founded in 2016 ·Backed by Viking Global Investors
React Foundation members. Core Contributors.
We are founding members of React Foundation and Core Contributors to React Native. You get direct access to people close to the decisions shaping the frameworks you use.
Open source since 2016. Our code runs in your app.
We contribute to React Native and maintain libraries across its ecosystem. Our code runs in apps used by millions of people every day.
39M+
Downloads / month67K+
GitHub stars300+
React Native commits100+ Enterprise clients with 7B+ users.
We work with teams shipping at real scale. You get a partner used to high-stakes products, not learning on your roadmap.
Agent Conf. The conference for the Agentic era.
The conference we built for the shift from writing code to orchestrating agents.
We are Codex Ambassadors.
We run meetups, workshops, and hands-on sessions that help teams learn Codex and apply it in real work.
10 years in React Native. Now shaping agentic engineering.
For a decade, we have helped define how teams ship with React Native. Now we are helping shape how they work with agents.
Founded in 2016 ·Backed by Viking Global Investors
React Foundation members. Core Contributors.
We are founding members of React Foundation and Core Contributors to React Native. You get direct access to people close to the decisions shaping the frameworks you use.
Open source since 2016. Our code runs in your app.
We contribute to React Native and maintain libraries across its ecosystem. Our code runs in apps used by millions of people every day.
39M+
Downloads / month67K+
GitHub stars300+
React Native commits100+ Enterprise clients with 7B+ users.
We work with teams shipping at real scale. You get a partner used to high-stakes products, not learning on your roadmap.
Agent Conf. The conference for the Agentic era.
The conference we built for the shift from writing code to orchestrating agents.
We are Codex Ambassadors.
We run meetups, workshops, and hands-on sessions that help teams learn Codex and apply it in real work.
Early to React Native.
Early to Agents.
Callstack was founded just months after React Native went public. Since then, we’ve contributed to the framework, grown the community, and helped teams ship cross-platform products at scale. In 2026, we made AI-native engineering the next chapter.
React Native is open-sourced by Meta, sparking a new era in mobile development.
Callstack is founded in Wroclaw, Poland, just months after React Native goes public.
We launch React Native EU, the first conference dedicated to React Native.
Callstack grows beyond 200 people, with teams working across countries, clients, and open source.
We launch our AI-focused offering, bringing agentic infrastructure, AI-native delivery, and enterprise AI adoption into the React Native stack.
Backed by Viking Global Investors for what comes next.
In 2025, Viking Global Investors backed Callstack’s next stage of growth. That support lets us keep investing in the work that compounds: open source, React Native expertise, AI-native infrastructure, and senior engineering teams built for long-term client outcomes.
JOIN US
Build with agents before everyone else does.
You'll work on the tools, infrastructure, and products defining AI-native engineering, alongside core contributors and open-source maintainers.
Worth your time, by engineers.
React Native Wrapped 2025: A Month-by-Month Recap of The Year
The first edition of React Native Wrapped looks back at the year RN turned 10 and the ecosystem doubled down on the New Architecture. It provides a month-by-month record of 2025, covering major framework releases, the Legacy Architecture freeze, React 19 integration, and notable developments across tooling, performance, styling, native modules, Expo, and platform adoption.
Agent Conf
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App Store Connect CLI, Agents, and Mobile Release Automation With Rudrank Riyam
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From Native to React Native for TV: The Zattoo Case
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Writing Custom Renderers for React
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