Crypto Payments Super-App Mobile Client (React Native)
A crypto payments super-app
Overview
The cross-platform mobile client for a crypto payments super-app, built in React Native and TypeScript. It bundles a multi-chain wallet, payments, KYC onboarding, biometric security and merchant features into a single consumer app for iOS and Android.
The Challenge
Delivering a payments super-app means combining a self-custody crypto wallet, fiat-grade UX, regulatory KYC, hardware-backed security and rich native features, all in one performant, store-shippable mobile app maintained over years.
What We Built
A feature-sliced React Native app (src/ split into app, entities, features, processes, screens, shared, widgets) with native iOS and Android projects. Highlights observed in the stack:
- Web3:
ethers/viem,@solana/web3.js, WalletConnect (@walletconnect/sign-client,web3wallet), input-data decoders and keccak/sha3 crypto primitives for multi-chain wallet operations. - Identity & security: Sumsub and Ondato KYC SDKs, biometrics, encrypted/secure storage, screenshot prevention, and a document scanner/vision camera for ID capture.
- State & data: Redux Toolkit with Redux Persist, MMKV high-performance storage, React Query-style data flows, React Hook Form + Yup validation.
- Platform: Firebase (Analytics, Crashlytics, Messaging, App Check, Remote Config), Sentry monitoring, i18next localization, Fastlane release automation, and a private OpenAPI-generated client SDK module.
Technologies & Approach
React Native for a single TypeScript codebase across platforms; a feature-sliced architecture for scalability; native Web3 libraries for multi-chain support; enterprise KYC and hardware security SDKs for compliance; and a full observability/release toolchain (Firebase, Sentry, Fastlane) for production operation.
Outcome / Impact
Shipped and maintained the flagship consumer app for the super-app across roughly two years (2023–2025), integrating wallet, payments, multi-chain crypto, KYC and merchant capabilities into one production mobile product.
Capabilities Demonstrated
- Building and maintaining production fintech mobile apps in React Native
- Multi-chain Web3 integration (Ethereum, Solana, WalletConnect) on mobile
- Compliant onboarding with KYC SDKs, biometrics and hardware-backed secure storage
- End-to-end mobile delivery: state architecture, localization, observability, Fastlane release automation