
Deliver stable releases with confidence—even at scale
We help teams strengthen quality assurance in React Native apps by introducing test automation, platform-specific validation, and scalable QA processes that keep up with team and product growth.

Why quality assurance becomes harder as your React Native app grows
Manual testing doesn’t keep up as applications and teams expand. Without strong automation, cross-platform validation, and clear quality ownership, bugs, regressions, and missed edge cases multiply—delaying releases and eroding user trust.
Lack of built-in testing and monitoring
React Native does not provide a complete testing stack. Without structured unit, integration, and runtime testing, teams struggle to maintain consistent app behavior across releases.
Lack of built-in testing and monitoring
React Native does not provide a complete testing stack. Without structured unit, integration, and runtime testing, teams struggle to maintain consistent app behavior across releases.
Platform differences are hard to validate
React Native abstracts platform APIs, but device-specific behaviors still vary. Without automated cross-platform testing and real device coverage, critical issues are missed during development.
Platform differences are hard to validate
React Native abstracts platform APIs, but device-specific behaviors still vary. Without automated cross-platform testing and real device coverage, critical issues are missed during development.
Scaling teams without scaling quality processes
Without standardized testing practices, ownership models, and automated quality gates, growing teams introduce inconsistencies that make stable releases harder to achieve.
Scaling teams without scaling quality processes
Without standardized testing practices, ownership models, and automated quality gates, growing teams introduce inconsistencies that make stable releases harder to achieve.
Scaling mobile test automation for a global car manufacturer
For a global car manufacturer delivering multiple white-label apps across markets, we introduced scalable test automation for their React Native mobile codebase.
By combining Appium and Browserstack, we enabled end-to-end test coverage across dozens of branded app variants—fully integrated into CI/CD pipelines for every release.
120+
end-to-end test cases executed on the CI
>99.95%
crash free sessions

Confidence in every release, no matter the scale
A quality foundation built on automation, so your app can grow without introducing regressions.
Cross-platform QA strategy
A tailored QA approach for React Native—aligning tools, environments, and processes to ensure full coverage across iOS, Android, and web.
Automated testing pipelines
End-to-end and integration tests fully embedded into CI/CD—providing reliable, repeatable validation at every step.
Manual validation for critical flows
Hands-on QA coverage for high-risk features, edge cases, and UI regressions—complementing automation where it matters most.
Test coverage and quality metrics
Clear visibility into what’s tested, what’s missing, and what impacts user trust—helping teams prioritize with confidence.
Team training
A scalable QA workflow your team can own—covering test case management, release checklists, and continuous feedback loops.
AI-native E2E testing
End-to-end test automation powered by GPT-driver—enabling anyone to write test specs in plain English and validate complex flows without code.

Make performance optimization part of your delivery process
React Native performance can’t be fixed once—it has to be built into how you ship. By applying structured methods like DMAIC and adding tools like Reassure to your CI, you can catch regressions before they reach production, validate improvements with real data, and create a workflow where performance is measured, not guessed.
Enterprise-grade QA services built for React Native
Build and maintain automated test coverage
We implement and expand automated test suites—covering regressions, flows, and edge cases with integration into your CI/CD.
Run manual QA where it matters most
We provide real-device testing for complex flows and platform behaviors that can’t be reliably covered by automation.
Test across devices, OS versions, and platforms
We validate your app’s behavior in real-world conditions using device farms—ensuring stability across iOS, Android, and various device configurations.
Extend your team with QA expertise
Our engineers join your team directly—filling gaps in QA ownership, executing tests, and helping your team ship with confidence.

Why leading companies work with Callstack
Meta Official Partners
We are official Meta partner for React Native, co-organizers of React Conf and hosts of React Universe Conf.
Working at scale
We know how to make React Native work at enterprise scale, both technically and organizationally.
React Native Core Contributors
We don’t just use React Native to build cross-platform apps, we help shape it for millions of developers.
Team at scale
We’re a team of 200+ engineers ready to start fast and scale with your needs.
Enterprise-friendly
We hold ISO certifications and follow strict security standards to make onboarding smooth and compliant.
Wide range of services
As a partner for your full application lifecycle, we offer a full range of services around React and React Native.

FAQs
Testing React Native apps across iOS, Android, and real devices brings unique challenges at scale. These are the most common questions we get from teams looking to strengthen coverage, catch issues earlier, and ship more reliable releases.
Yes. We often augment in-house teams—handling specific test scopes, bringing in automation expertise, or supporting manual validation as needed.
No. While we specialize in automation, we also provide manual QA for complex flows, UI regressions, or areas where human testing is essential.
We test on real devices across iOS and Android—validating behavior that emulators and automation tools may miss, especially in OS-specific edge cases.
Absolutely. We work with popular CI/CD provides as well as bespoke infrastructures to hook testing into your existing pipelines.
We set up and maintain unit tests, integration tests, and end-to-end UI tests—depending on where gaps exist and what delivers the most value.
We track coverage across key flows and use metrics like pass rates, failure patterns, and P95 performance to monitor test reliability and impact over time.
Yes. Whether you're launching or maintaining, we can introduce or improve QA practices without disrupting ongoing development.
Need a QA partner who understands React Native at scale?
We work with engineering teams to deliver stable, well-tested apps—combining automation, manual validation, and platform expertise to help you ship with confidence.