Full-Stack Developer

For our client, we're looking for a Senior Fullstack Developer to join client team and contribute to its continued growth. Frontend (React): Build modern, responsive, and accessible UI components using React / Next.

js; Implement clean, modular front-end architecture using hooks and component; libraries; Optimize rendering performance and frontend UX across devices; Collaborate with designers to turn UI/UX into functional interfaces. Backend (Node. js): Design and implement RESTful or GraphQL APIs using Node. js / Express / Nest.

js; Build scalable microservices with proper separation of concerns; Work with relational and NoSQL databases (PostgreSQL, MongoDB, etc.) ; Implement authentication, authorization, and role-based access control; Integrate with third-party APIs and services (payments, notifications, etc.)

; Ensure robust error handling, logging, and testing.

Requirements

5+ years of experience in fullstack web development; Deep knowledge of JavaScript/TypeScript across both frontend and backend; Proficiency with React (or Next. js) and related frontend tooling (Webpack, Vite, etc.) ; Strong backend skills in Node. js and one or more frameworks (Express, Nest. js, etc.)

; Solid understanding of database design and query optimization (PostgreSQL, MySQL, MongoDB); Experience with API design, authentication flows, and JWT/OAuth2; Experience with Git, CI/CD, and automated testing; Strong architectural and problem-solving skills; Ability to communicate clearly, collaborate cross-functionally, and mentor others; Very good English language written and verbal communication skills.

Nice to have: Experience with Cloud platforms (AWS, GCP, Azure); Experience with Docker, containerized deployments, or Kubernetes; Familiarity with serverless architecture (AWS Lambda, Firebase Functions); Exposure to microfrontend or monorepo setups (Turborepo, Nx); Familiarity with Agile processes, Jira, Scrum/Kanban boards.

The offer: Warsaw (Poland) - fully remote work (B2B contract); Vilnius (Li