Your React & React Native Development Experts

Work with expert React and React Native developers to solve challenges, ship faster, and scale with confidence, on every platform.

Valued by clients worldwide
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Contributing since 2016

Callstack was founded a few months after React Native was released to support developers and companies looking to use it, without having to worry about the complexity of building native apps.

Since then, we’ve helped teams of all sizes succeed with React Native, while contributing to the core framework and maintaining key open source tools.

Mike Grabowski
Founder & React Native Core Contributor
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Services

When your team needs direction, 
we bring clarity

Work with expert React and React Native developers to solve challenges, ship faster, and scale with confidence, on every platform.

Consulting

Get expert support all things React

Get expert help from Core Contributors with 9+ years of experience in React and React Native, whether you’re solving a specific issue or planning architecture that scales.
Product Development

Launch faster on all platforms

Build your product once for 10+ platforms, from iOS and Android to tvOS, Vision Pro, and beyond; saving time, reducing development costs, and maximizing reach.
Enterprise Solutions

Scale React at your organization

Adopt React Native at scale with the right architecture, shared codebase, and built-in monitoring; designed to support complex teams and long-term growth.
AI Engineering

Ship production-ready AI cross-platform

Build reliable AI features from on-device models to knowledge-connected assistants, designed to scale in real products.
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Valued by clients worldwide
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Contributing since 2016

We are proud members of React community

React Native
Core Contributors

If you're looking for skilled and trusted React Native developers, Callstack is definitely the way to go.

Tom Occhino
Director of Engineering
@
Meta
20mln+
Downloads on npm
10k+
Stars on GitHub
250+
Commits to React Native

The team at Callstack are the most experienced engineers in the React Native community.

Nader Dabit
Senior Developer Advocate
@
AWS
Co-Organizers

Their ability to deliver, and follow through, is unparalleled in the React Native ecosystem.

Matt Hargett
Principal Software Engineer
@
Roblox
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Open source

Our libraries are used by millions of developers worldwide

If you're creating an app with React or React Native, there's a good chance our code is already running in your application.

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React Universe

We build apps in the React Universe

Instead of splitting development across multiple languages, platforms, and teams, we combine front and back-end development with cross-platform capabilities using a single programming model.

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Case studies

We solve all React Native challenges, from brownfield to greenfield

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Product Development
Mobile App Development
Module Federation Development

React Universe App: Networking Evolved with Liquid Glass

63%

adoption rate; majority of attendees registered in the app

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Consulting
New Architecture Migration
Quality Assurance

Migrating Questrade Edge Mobile to a Faster, More Scalable Architecture

33%

fewer re-renders across most features

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Product Development
Migration to React Native
Code Sharing

Migrating a Legacy React Native App to Expo for Faster Builds and Simplified Releases

6x

faster builds after replacing Jenkins with EAS

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Enterprise Solutions
Migration to React Native
React Native Performance Optimization

Building Scalable Observability for a High-Growth React Native App

3→1

analytics systems unified into a single interface

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Enterprise Solutions
Migration to React Native
New Architecture Migration

Training HelloFresh Engineers to Build Production Apps With React Native

2.8x

increase in knowledge over 8 weeks (25% → 71% assessment scores)

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Product Development
Mobile App Development
Next.js Development

Building a browser-based React Native playground for Expo

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Consulting
Mobile App Development
Migration to React Native

Migrating iOS and Android Apps to React Native for AutoZone

2x

growth in mobile user base during the migration period

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Enterprise Solutions
Streaming App Development
React Native Performance Optimization

Optimizing Android TV Startup for Global Streaming Platform

5%

faster startup time on FireTV and FireHD devices

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Product Development
Module Federation Development
Expo Development

Launching a High-Performance React Native App on Samsung TV

5

platforms under one RN codebase: tvOS, FireTV, Tizen, LG, Vizio

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Consulting
React Native Development
React Native Upgrades

Creating React Native SDK Wrapper for Rive

100k

weekly downloads on npm

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Consulting
React Native Performance Optimization
React Native Development

Enhancing Performance of Momo's Super App With Re.Pack

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Product Development
Code Sharing
React Native Development

Modernizing 7Cup's React Native Codebase and Adding Platform Features

130%

increase in users post-upgrade

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Enterprise Solutions
Mobile App Development
Next.js Development

Launching White-Label Super App for Zephyr Cloud With Re.Pack

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insights

Your cross-platform knowledge hub

We don't follow best practices, we set them
React Native Core Contributors
Trusted by Meta, Microsoft, and the community
We don't follow best practices, we set them
React Native Core Contributors
Trusted by Meta, Microsoft, and the community
We don't follow best practices, we set them
React Native Core Contributors
Trusted by Meta, Microsoft, and the community
We don't follow best practices, we set them
React Native Core Contributors
Trusted by Meta, Microsoft, and the community
We don't follow best practices, we set them
React Native Core Contributors
Trusted by Meta, Microsoft, and the community
We don't follow best practices, we set them
React Native Core Contributors
Trusted by Meta, Microsoft, and the community
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hire us

Your challenge is next!

Let us know what you’re building,
we are always happy to help!

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Valued by

We think they are great developers and we learned a lot from them.

Robin Cussol
Frontend developer
@
Kiwi.com

Having Callstack is a wonderful experience and gives us the ability to move so much faster than we could without them.

TC Davis
Product
@
Expo

They took our team from 'zero to hero' in React Native

Nguyễn Kỳ Thanh
Chief Marketing Officer
@
OneHousing

Despite the geographical distance, our collaboration has been successful with strong deliveries on time.

Martin Rolinski
CEO
@
We Are Voice