
Scale features through independent mini apps.
A modular host shell
A stable host shell handles routing, layout, and runtime loading of mini apps, each owned, built, and deployed by a separate team.
Update without redeploy
Push fixes, features, and new mini apps with no store review or full release. Southern Glazer's cut releases from weeks to seconds.
Sandboxed mini apps
Each mini app runs in an isolated, sandboxed environment, so independently built modules stay safe from one another.
Open to third parties
Expose APIs, shared libraries, and contracts so external teams ship updates without conflicts or touching the host.
Validate in one sprint
Validate the super app model against your product in one sprint: a working host-and-mini-app setup on Re.Pack, plus a scaling roadmap.
You own everything we build
Clear structure, docs, and naming conventions so your team takes over with confidence and owns the platform after handover.
Scope → Build → Scale
Take one product from scope to scale.
Scope
We map your problem, align on deliverables, and define success metrics. No surprises once work starts.
Build
Engineers ship with AI-native workflows from sprint one. Code, decisions, and ownership, not discovery decks.
Scale
Expand scope, add platforms, or hand off to your team. The stack, tooling, and raised bar stay with you.
Case studies
What shipping at AI speed looks like
Why teams bet on Callstack
From billion-user apps to React Native core, this is why teams choose Callstack when they need to move fast and get it right.

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.
Let’s find the right path for your product.
Whether you’re planning new work or unblocking an existing product, we’ll help you choose the right path forward.
Can I launch with one mini app and add more over time?
Yes. Super apps are built to evolve, start small and onboard new features or services independently as your product grows.
How do you manage independent deployments for mini apps?
We register each mini app through a discovery server, allowing the host to dynamically load the latest approved version. Teams can deploy independently without touching the host or other modules.
What if my mini apps are built by different teams or vendors?
That’s exactly what super apps are designed for. Each team can own their own module, repository, and release cycle, without breaking the host app.
Does this approach work outside of a monorepo?
Absolutely. Our setup supports both monorepo and multi-repo models, giving you flexibility in how teams structure and collaborate on code.
Can each mini app also work as a standalone app?
Yes. Mini apps can be built to run independently for local development or testing, while still integrating seamlessly into the host.
How do you handle versioning and compatibility between host and mini apps?
We use content hashing and shared contracts to manage compatibility at runtime. This ensures the host app only loads compatible mini apps.
Will this architecture increase app size or load time?
No, microfrontends are loaded on demand, so users only download what they need, keeping your app lightweight and responsive.
Can we validate the super app model before committing to a full build?
Yes. In one sprint we deliver a working host-and-mini-app setup on Re.Pack, plus a scaling roadmap, so you can validate the model against your product before going further.
How do AI agents fit into the build, and how do you keep it secure?
Agents move the work forward while our experts make the calls, so engineers direct the build and own every decision. The same sandboxing that isolates mini apps keeps independently built modules safe from one another.
Build your super app with the Re.Pack team
We design and build modular, production-ready super apps for independent teams and faster releases. Let's scope yours.
We had been struggling with React Native application performance until we met Callstack.
Open Source
Want to build it on your own?
We open-source the tools behind our delivery model.
Use them, fork them, or let us run them for you.
Insights






























































