Lead React Native Developer

Sii Ukraine is a subsidiary of Sii Poland — the leader in IT, engineering, and consultancy services with over 7500 IT experts in Poland and more than 250 prestigious customers. We are looking for ambitious and top-quality professionals to join our project teams.

As a Lead React Native Developer, you will join a long‑term strategic project for one of our clients, a global provider of technology solutions in the online trading domain.

This role sits at the heart of a key revenue initiative. As the Lead React Native engineer across the entire platform, you will shape the mobile architecture, drive engineering standards, and contribute directly to the success and growth of the product.

Tasks:

• Design and develop high-quality, production-ready features for customer’s React Native application
• Collaborate with product managers, designers, and backend engineers to deliver features with excellent UX
• Implement secure authentication flows and session management
• Optimize application performance, focusing on responsiveness and efficiency
• Resolve complex technical issues and improve application architecture
• Participate in code reviews and mentor junior developers
• Develop and maintain automated tests to ensure reliability
• Work in an Agile environment, applying methodologies such as pair programming, test-driven development (TDD), and behavior-driven development (BDD)
• Take care of app submissions to stores

Requirements:

• 8+ years of professional experience with React Native development
• Strong JavaScript/TypeScript proficiency
• Familiarity with charting libraries and real-time data visualization
• Understanding of RESTful APIs and secure data handling
• Knowledge of React Native performance optimization techniques
• Familiarity with native modules and third-party integrations
• Experience with automated testing frameworks for React Native
• Understanding of App Store and Google Play submission processes
• Tax residence in Ukraine is required