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React Native has been reshaping mobile app development since it was first created, providing a versatile framework that lets developers build cross-platform mobile applications quickly.
In fintech specifically, that efficiency can be incredibly beneficial. However, you need developers who can help build your platforms correctly.
A payment confirmation screen that drops frames, a KYC flow that re-renders unnecessarily, or a token stored in cleartext are problems that have real consequences in regulated financial products.
Without implementing specific best practices, you won't be able to utilize React Native to its full potential.
Let’s look at the core practices for performance, architecture, state management, and security that fintech teams building on React Native should prioritize.
If you're looking to hire React Native developers with fintech production experience, we can assist. Our pre-vetted talent pool means you can connect with the right people in as little as 3-5 days.
React Native is an open-source framework originally developed by Facebook (now Meta).
It allows developers to use JavaScript and React to build cross-platform mobile apps, where a single codebase can be deployed to both iOS and Android, which saves significant time and development costs.
The framework is very popular, partly because React Native bridges JavaScript to native platform components rather than rendering in a WebView. The result is performance close to native apps, making it viable for most mobile development needs, including fintech.
The exception is apps with the most extreme performance requirements.
Our React Native developers like to use the framework because of the rich ecosystem of libraries, seamless integration with native modules, and a large community that has grown significantly over the past few years.
Related Reading: Companies Using React Native
Native development can give you better performance and access to platform-specific features. However, separate codebases for iOS and Android cost more in time and resources.
To decide whether code reusability is worth any performance trade-off, consider your most complex UI elements.
Are you running graphics-intensive animations or real-time video processing that would suffer in React Native?
For most fintech use cases, such as those involving transaction lists, account dashboards, payment flows, and KYC onboarding, React Native handles the workload well.
iOS and Android devices display at least 60 frames per second, giving the system at most 16.67ms to generate each frame. Missing that window drops a frame, which users feel very quickly.
Most performance work fails because developers don’t target the right work. Optimizing useMemo calls, for example, while an async waterfall adds 600ms of waiting time, doesn't move real-world metrics.
For this reason, we recommend targeting async waterfalls first, then reducing bundle size, and only then addressing re-renders.
There are a couple of other things you need to consider:
A well-organised project structure makes the codebase readable and maintainable, both for your current team and for developers onboarding later.
For fintech products in particular, where compliance requirements change the scope of specific features regularly, keeping related code together is practically useful.
Here is an example of a layout we recommend:
src/
components/
screens/
navigation/
hooks/
services/
store/
utils/
types/
assets/
Feature-based or domain-driven structure scales better at larger codebases. Rather than placing all hooks in one folder globally, organise by domain: features/authentication/, features/payments/, features/kyc/. When a regulatory requirement changes how KYC works, everything relevant is in one place.
Keep files flat where possible. Avoid deeply nested folders unless the project genuinely requires it.
Long relative import paths like ../../../components/Button make code harder to read and maintain. Set up compiler path aliases to shorten them:
import Button from '@components/Button';
import Header from '@components/Header';
Configure these in babel.config.js using babel-plugin-module-resolver. It's a small setup cost that pays off consistently.
There is little debate when it comes to TypeScript for production React Native codebases, especially in fintech.
TypeScript provides static type checking that catches errors at compile time rather than at runtime. In a financial application where a currency amount passed as a string instead of a number produces incorrect arithmetic, that compile-time safety is meaningful.
You need to enable strict mode and type your component props, API responses, and navigation parameters explicitly. Make sure to avoid any.
In some cases, our developers must use it, so they make sure that it is only temporary and mark it with a TODO comment.
type Props = {
amount: number;
currency: string;
onConfirm: () => void;
};
export const PaymentSummary = ({ amount, currency, onConfirm }: Props) => { … };
Inline styles cause performance issues and make code harder to maintain.
Use StyleSheet.create() or a separate .styles.ts file for larger components.
You should also abstract constants (colours, spacing, font sizes) into a unified theme object rather than scattering hardcoded values across components:
import { Colors, Spacing } from '../theme';
const styles = StyleSheet.create({
container: {
padding: Spacing.md,
backgroundColor: Colors.primary,
},
});
NativeWind (Tailwind CSS for React Native) is another option worth considering for teams already familiar with the Tailwind utility approach.
Styled-components have documented performance issues in React Native, so it’s always worth checking current benchmarks before adopting them.
Keep functions short and focused. Our developers recommend 10–25 lines as a reasonable target. If a function scrolls off-screen, it probably needs refactoring.
One function should have one purpose:
// Avoid
function loadUserAndRenderAndLog() { }
// Prefer
function fetchUser() { }
function logUserLoad() { }
It is also best to use clear, descriptive names.
Avoid abbreviations, particularly in fintech code where regulators may ask for explanations. Something like processKYCVerification() is considerably clearer than procKYC().
You need to keep in mind that the application is likely to grow in the future, and that developers may come and go as part of a larger team.
Efficient state management ensures the app remains performant and manageable as the codebase grows.
For fintech apps, React Query (or TanStack Query) handles server state particularly well, since it manages caching, background refetching, and stale-while-revalidate patterns that keep account balance displays current without over-fetching.
Always avoid immutable state mutation errors by returning new state rather than modifying existing state directly.
Use native-driven navigation via React Navigation or Expo Router.
These leverage underlying native container views (react-native-screens) to preserve system memory and provide smoother transitions than JavaScript-based navigation alternatives.
Native stack navigators have better out-of-the-box performance because their transition animations run on the native main thread, unaffected by JavaScript thread activity.
Security in React Native fintech apps requires deliberate decisions at every layer where sensitive data touches the application.
Never save authorization tokens, personal identifying information, or API credentials inside AsyncStorage. It stores data in clear text, accessible to any process on the device.
Use hardware-backed secure storage instead:
If you are handling payment credentials or access tokens, this is not optional.
We often see these practices appear in security reviews, and, depending on your compliance scope, they may be a PCI DSS or regulatory requirement.
Before adding any open-source package, verify it is actively maintained.
If you are unsure, look for things like recent commits, active issue tracking, and compatibility with current React Native versions.
Major iOS or Android system updates can break unmaintained packages in ways that block app store submissions, and discovering that mid-release is costly.
It is also a good idea to minimize your dependence on third-party libraries as a general rule. Too many can make your app too large and create a larger attack surface for security vulnerabilities.
It is best to strip console.log statements before production builds. They bottleneck the JavaScript thread and occasionally expose sensitive data in device logs.
Our developers like to use babel-plugin-transform-remove-console to handle this automatically.
For Android, enable R8 native code shrinking in your build configuration to reduce final bundle size.
You should also test performance in release builds, not just development mode, since JavaScript thread performance suffers significantly in dev mode due to runtime warnings and error checking that don't exist in production.
Always implement crash analytics to monitor app health in production.
Firebase Crashlytics and Sentry both support React Native and can track both native crashes (iOS/Android) and JavaScript errors.
You can use ErrorBoundary components to catch JavaScript errors gracefully rather than letting them crash the app:
import * as Sentry from '@sentry/react-native';
class ErrorBoundary extends React.Component {
componentDidCatch(error, errorInfo) {
Sentry.captureException(error, { extra: errorInfo });
}
render() {
if (this.state.hasError) {
return <Text>Something went wrong.</Text>;
}
return this.props.children;
}
}
An unhandled crash during a payment flow or KYC verification may create confusion about whether a transaction has been completed.
Testing for every project is crucial, and in fintech, the stakes for untested flows are higher than in most domains.
Always spend time on end-to-end testing for compliance-critical flows.
A KYC onboarding flow that allows users to proceed without completing a required step, or a payment confirmation screen that submits without a genuine user action, creates regulatory exposure regardless of what the backend records.
Available tools include Jest for unit and integration tests and Detox for E2E testing on real devices and simulators.
Expo has been the officially recommended framework for new React Native projects for several years now.
It simplifies the development process by providing comprehensive tools and services for React Native, allowing you to focus on writing high-quality code without getting bogged down in native configuration.
Expo provides access to native APIs (camera, location, notifications, sensors, biometric authentication) without requiring manual native code.
For fintech apps that need Face ID or fingerprint authentication, Expo's expo-local-authentication covers the common cases without additional native module configuration.
Expo's over-the-air (OTA) update capability lets you push updates directly to users without going through the app store review process, which can be useful for non-binary updates.
For compliance-related changes that affect the app binary, the standard App Store and Play Store review process still applies.
If you're deciding whether to use React Native for a fintech product, we recommend that you focus on the performance-intensive features.
Are you running complex animations, real-time video processing for liveness detection in KYC, or graphics-heavy experiences that would suffer in React Native? If not, React Native is likely the right choice.
On top of that, you will also need to consider your team. Developers already familiar with JavaScript and React can reach productive React Native velocity faster than teams that would need to learn Swift and Kotlin simultaneously.
In fintech projects, you will need to look for experience specifically in payment integrations, secure storage implementation, biometric authentication, and compliance-adjacent UI patterns.
At Trio, we place pre-vetted React Native developers with fintech production experience in 3–5 days at $40–$80/hr.
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