React Native Developer (Blockchain/Crypto)

The client is an innovative global fintech leader behind USDT, the world’s largest and most widely used stablecoin.

This role focuses on building high performance, intuitive mobile applications that integrate crypto wallet and DeFi functionality. You will work in a fast-paced environment alongside senior backend engineers, product managers and leadership to deliver secure cross-platform wallet experiences for a global audience.

Responsibilities

• Development
  Design, develop and maintain secure cross-platform mobile applications for iOS and Android using React Native (Expo).
  Work closely with designers to ensure the UI is clean, fast and accessible.
  Write clean, testable, and well-documented code, following best practices.
• Integration
  Integrate JavaScript SDKs, crypto wallet libraries, backend services and low-level native modules into mobile applications
  Work with Bitcoin / Web3 / blockchain APIs and wallet backends.
  Implement and manage wallet functionality: addresses, balances, transactions, seed phrases, private keys (with secure handling only).
• Collaboration
  Work closely with backend, product and design teams to deliver innovative crypto wallet and DeFi features.
  Participate in architecture discussions, code reviews and technical decision-making.

• Security & Reliability
  Implement mobile security best practices: secure storage, encryption, device integrity checks, protection from common attack vectors.
  Contribute to performance optimization, monitoring and reliability of mobile apps used at global scale.

   

Key Requirements

• Deep experience with React and React Native (Expo)
• Strong knowledge of JavaScript and ES6+, and familiarity with modern front-end tooling.
• Experience with Redux and related React ecosystem fundamentals.
• Proven background in crypto or wallet development (Bitcoin, Web3, wallets, private keys or similar technologies).
• Understanding of decentralized systems and concepts like public/private keys, signing, transactions, and fees.
• Strong experience integrating REST APIs and WebSockets; real-time data handling.
• Experience with native modules (e.g. in C++) and low-level integrations.
• Hands-on experience in Swift or Objective-C (iOS) or Kotlin or Java (Android) for low-level mobile integrations.
• Familiarity with CI/CD pipelines for mobile deployments.
• Good understanding of mobile security: secure storage, key management, encryption, secure communication.
• Comfortable working in a remote, distributed team, communicating in English (written and spoken).

Nice to Have

• Experience with hardware wallets or secure elements.
• Knowledge of Layer 2 solutions, sidechains, or Lightning Network.
• Background in cryptography or security engineering.
• Experience with performance optimization and profiling for mobile apps