We’re looking for an experienced developer with strong expertise in Node.js, React, and React Native, who writes reliable, efficient, and maintainable code. Responsibilities Develop and maintain backend services using Node.js (TypeScript + JavaScript for legacy code); Build and enhance web and mobile applications using React and React Native (Expo); Design, implement, and optimize RESTful and GraphQL APIs; Work with relational and non-relational databases (PostgreSQL, MongoDB, Cassandra); Integrate external services (payments, delivery, analytics, CRM); Participate in architecture design and code reviews; Nice to have Experience developing high-load or distributed systems; Familiarity with message queues, caching, and microservices architecture; Knowledge of Redis, Kafka, or RabbitMQ; Basic experience with CI/CD pipelines and cloud infrastructure; Interest in scalability, fault tolerance, and system performance; Polish language; Leading skills; Requirements 5+ years of commercial experience with JavaScript / TypeScript; Strong knowledge of Node.js, React, and React Native (Expo); Strong knowledge of Next.js, Nest.js and Apollo Deep understanding of SQL and NoSQL databases (PostgreSQL, MongoDB, Cassandra); Solid grasp of asynchronous programming, API design, and data modeling; Experience working with Git, Docker, and basic AWS services; Ability to write clean, maintainable, and well-documented code; English — intermediate or higher (for documentation and communication).