Senior React Native Developer (f/m/x)

Join one of Europe's largest mobile platforms, delivering digital services used by millions of users across multiple countries in Europe and North America. Built on a multi-module architecture, the platform enables rapid product development, high code reusability, and continuous expansion into new business areas.

As a Senior React Native Developer, you will play a key role in shaping the architecture of a big mobile ecosystem, driving technical decisions, mentoring other engineers, and delivering high-quality solutions at scale.

Your tasks

• Design, develop, and maintain complex mobile applications using React Native and TypeScript

• Drive architectural decisions and contribute to the evolution of our multi-module platform

• Lead technical discussions and participate in solution design

• Review code, mentor team members, and promote engineering best practices

• Collaborate closely with Product Owners, UX Designers, Backend Engineers, QA Engineers, and Architects

• Improve application performance, reliability, scalability, and maintainability

• Contribute to CI/CD processes and development tooling

• Support the integration of native mobile capabilities and third-party services

• Identify technical debt and proactively drive improvements across the codebase

Requirements

• At least 5 years of commercial software development experience, including at least 4 years with React Native

• Proven track record of building and maintaining large-scale mobile applications

• Strong expertise in TypeScript, modern JavaScript, and React Hooks

• Solid understanding of modular and multi-module application architecture

• Hands-on experience with MobX and React Query (TanStack Query)

• Knowledge of native mobile development concepts and creating native modules for iOS and Android

• Practical experience with REST APIs, GraphQL, and form management solutions

• English and Polish proficiency at the B2 level or higher

• Residing in Poland required

Nice-to-have requirements

• Payment integrations and mobile wallet solutions

• Geolocation and location-based services

• Firebase services and analytics

• Mobile security best practices

• Observability and monitoring tools

• Background in large-scale international products

• Agile delivery experience (Scrum/Kanban)

What we offer

• Great Place to Work since 2015 - it’s thanks to feedback from our workers that we get this special title and constantly implement new ideas

• Employment stability - revenue of PLN 2.1BN, no debts, since 2006 on the market

• We share the profit with Workers - over PLN 76M has already been allocated for this aim since 2022

• Attractive benefits package - private healthcare, benefits cafeteria platform, car discounts and more

• Comfortable workplace – class A offices or remote work

• Dozens of fascinating projects for prestigious brands from all over the world

• PLN 1 000 000 per year for your ideas - with this amount, we support the passions and voluntary actions of our workers

• Investment in your growth – meetups, webinars, training platform and technology blog – you choose

• Fantastic atmosphere created by all Sii Power People

If you want to work on systems with high operational significance — apply now!