React Native Brownfield
Incrementally move your iOS and Android apps to React Native without breaking
Tooling for introducing React Native into existing native apps incrementally.
What you get
React Native supports only its latest three releases. We move you into that window, so you keep getting fixes and compatibility instead of running on a version that's already unsupported.
Fabric, TurboModules, Bridgeless, and C++ TurboModules turned on once we verify your dependency tree supports them.
We strip dead packages, deprecated APIs, and legacy config that block upgrades, so the next one costs less.
Work runs in a flag-gated branch. Your team keeps shipping features while we move the version underneath.
SDK targets and policies updated to current iOS and Android requirements, so releases don't stall.
The people shaping React Native do the upgrade, not engineers guessing at the changelog.
How we work together
Our senior engineers join your team to ship features, guide technical decisions, and strengthen delivery.
We take agreed work from technical planning to release, with clear responsibilities and progress you can see.
We address a performance, migration, or infrastructure challenge, or run training around your team’s needs.
Case studies




React Native Upgrades
Tell us where you are. A global coffee brand came back from 2 years behind: 52 breaking changes resolved, feature delivery never paused.
We had been struggling with React Native application performance until we met Callstack.

We’ll connect you with the right expert within 24 hours.
Still have questions?
The longer you wait, the more breaking changes and unsupported libraries pile up. A global coffee brand came back from two years behind with 52 breaking changes resolved, so even large gaps are recoverable.
Most upgrades run in weeks, not quarters, depending on how outdated the stack is and how many custom native modules you use. New Architecture adoption can extend the scope.
No. Work runs in a flag-gated branch, so your team keeps shipping features while we move the version underneath.
Yes. We align your dependency tree and strip dead packages, deprecated APIs, and legacy config, so the next upgrade costs less.
Yes. We turn on Fabric, TurboModules, Bridgeless, and C++ TurboModules once we verify your dependency tree supports them.
React Native supports only its latest three releases. We move you into that window so you keep getting fixes and compatibility instead of running on a version that's already unsupported.
Yes. We update SDK targets and policies to current iOS and Android requirements, so releases don't stall.
React Native Core Contributors do the work, the people shaping the framework, not engineers guessing at the changelog.