Rast Mobile

React Native App Development & Consultancy

React Native apps,
built with mobile in mind.

We help teams carry their React and TypeScript experience into iOS and Android without ignoring the differences between the two platforms. We can start a new app with Expo or bare React Native, or take responsibility for upgrades, performance, native modules and store releases in an existing project.

Where we help with React Native

A new mobile product,
or an existing app that needs careful work.

We can own the application end to end or work with your team on one defined problem. Before choosing libraries, we look at the product, the native requirements and how the team plans to maintain it.

Build a React Native app from scratch

We set up the TypeScript structure, navigation, API contract, design system, development environments and release process, then deliver working iOS and Android versions.

Improve or upgrade an existing app

We review the code and native projects before changing versions. Dependencies, New Architecture compatibility, Gradle, CocoaPods and Xcode settings are handled as one upgrade plan.

Connect backend and native capabilities

We integrate REST, GraphQL, WebSocket, notifications, maps, camera, biometrics, deep links and background work around the way the app is used.

Make builds and releases repeatable

We set up signing, environment configuration, CI builds, internal distribution, TestFlight and Google Play test tracks, with Expo EAS or the project’s own pipeline.

How we build React Native apps

One JavaScript codebase,
two mobile platforms to respect.

React Native shares a large part of the product code, but iOS and Android still have different build systems, permissions and interaction details. We plan for those differences instead of hiding them behind packages.

Expo or bare React Native

The decision depends on native dependencies, update needs, build control and the existing codebase. We do not choose bare React Native for control we will never use, or Expo when it would constrain the product.

TypeScript boundaries and predictable state

Screen state, server data and persistent client state are kept separate. React Query, Redux Toolkit, Zustand or Context are selected for the job they need to do, not placed in one global store by default.

API, real-time and offline data

We design API calls, caching, local storage, retry rules, pending actions and sync conflicts together. When the connection drops, data should not disappear and the user should know what is waiting.

Native modules and the New Architecture

We check library compatibility with the New Architecture and write focused Swift or Kotlin modules when a package cannot meet the requirement. Codegen, Turbo Native Modules and Fabric are used where they solve a real integration need.

Performance measured in release builds

Startup, re-renders, long lists, JavaScript work, memory and native traces are inspected on physical devices with Hermes, React Native DevTools, Android Studio and Xcode.

Tests around the flows that matter

We use unit and component tests for business behaviour, then cover login, payment, offline work or another critical journey with device-level end-to-end tests.

Selected mobile product work

The framework can change.
The product responsibility does not.

Not every product below uses the same framework. They show the field, commerce, real-time and integration problems our mobile team has solved. Ask us for the React Native work closest to your product and we can share it without exposing confidential client information.

Before a React Native project starts

Questions we usually answer
in the first technical call.

We use whichever fits the product. Expo is a strong option when its modules and build workflow cover the requirements. We choose bare React Native when the app needs deeper control over native projects, has custom native code or must fit into an existing iOS and Android setup.

Yes. We first check the React Native version, TypeScript setup, third-party libraries, Gradle, CocoaPods and Xcode configuration. We also identify New Architecture compatibility before planning the upgrade in steps, so the team does not lose weeks to one oversized version jump.

Yes. If an existing package is not suitable, we can write the required Swift or Kotlin code and expose a focused, typed interface to React Native. We also review whether a Turbo Native Module or Fabric component is the right fit for the current architecture.

We reproduce the issue on a physical device and a release build first. Then we inspect startup time, unnecessary renders, long lists, JavaScript work, memory and native traces with React Native DevTools, Android Studio and Xcode. We measure before changing code.

Yes, when the workflow is designed for it. We decide which data stays on the device, how pending actions are queued, what happens when records conflict and what the user sees while the connection is unavailable.

Yes. We can manage signing, build profiles, internal testing and App Store or Google Play releases. When an over-the-air update is suitable, we define channels and rollback rules carefully; a change to native code still requires a new store build.

Tell us what you are building with React Native.

A short note about the product, the current codebase and the problem is enough for the first conversation.

Discuss your React Native project