Frontend Developer (React Js / Next Js)

Location: Poland Job Overview React and Next.js | 4 to 6 years This role is responsible for building reliable, responsive user interfaces from approved designs and API contracts. The developer should be able to deliver features independently, diagnose browser issues and contribute maintainable, well-tested code. Must Have Skills • Strong experience with React, Next.js, TypeScript and hooks-based component development. • Good understanding of component lifecycle, effects, memoisation and techniques for preventing unnecessary re-renders. • Experience with Next.js, Vite or a comparable modern front-end build framework. • Experience with Zustand, Redux Toolkit or a similar state-management library, including correct and efficient use of selectors. • Strong HTML5, CSS3 and SCSS skills, including responsive layouts, semantic markup and scoped styling. • Working knowledge of accessibility fundamentals, including keyboard navigation, focus management and appropriate ARIA usage. • Experience using a design system such as IBM Carbon, Material UI or an equivalent component library. • Ability to implement interfaces accurately from Figma designs or other visual specifications. • Experience integrating REST APIs and handling loading, error, empty and partial-data states. • Experience with polling, request cleanup and defensive handling of incomplete or unexpected API responses. • Working knowledge of environment configuration, package management and front-end build processes. • Experience writing unit and component tests with Vitest or Jest and React Testing Library. • Strong browser DevTools debugging skills and experience resolving cross-browser issues. • Working knowledge of Git branching, pull requests, code reviews and collaborative delivery workflows. • Ability to write clean, reusable and maintainable front-end code. • Good knowledge of secure client-side development, including environment variables and safe logging. Good to Have Skills • Experience with animation libraries such as GSAP, Framer Motion or React Spring. • Experience with charting libraries such as Recharts, Chart.js, D3.js or High charts. • Hands-on experience with three.js, React Three Fiber, WebGL or the HTML Canvas API. • Familiarity with performance profiling, bundle analysis, lazy loading and dynamic imports. • Experience with internationalization libraries such as react-i18next or next-intl. • Experience with end-to-end testing tools such as Playwright • Familiarity with error boundaries, front-end monitoring and CI/CD pipelines. • Familiarity with Azure DevOps • Experience working in an Agile team using Jira and Confluence.