Senior React.js Developer

Roles and Responsibilities: Build scalable, performant frontend features using React.js, TypeScript, and modern JavaScript. Own features end-to-end: translate product and design requirements into polished, reliable user experiences. Work effectively within a mature React codebase that uses both class-based components and modern functional components with hooks. Develop, maintain, and enhance reusable UI components and contribute to shared component libraries/design systems. Manage complex client-side and server state using Redux Toolkit, React Query, and API-driven data flows. Build interactive dashboards, data visualizations, maps, graphs, drag-and-drop workflows, and rich-text editing experiences. Partner closely with product, design, backend, and QA teams to ship high-quality enterprise features. Improve frontend performance, accessibility, security, testability, and observability. Participate in code reviews, mentor junior engineers, and contribute to frontend engineering standards. Modernize legacy frontend code where appropriate, including safe migration from class-based React components to functional components and hooks. What we’re looking for Strong expertise in React.js, TypeScript, JavaScript, HTML, and CSS. Strong experience with React class-based architecture, including lifecycle methods, component state, props, composition patterns, error boundaries, and performance optimization. Experience building and maintaining both class-based React components and functional components using hooks. Experience with state management patterns, ideally Redux and Redux Toolkit. Experience integrating REST APIs and handling asynchronous server state; React Query experience is a plus. Strong understanding of component architecture, reusable UI patterns, responsive design, and cross-browser compatibility. Experience building complex enterprise applications with large datasets and multi-step workflows. Familiarity with frontend testing, debugging, browser performance optimization, and production monitoring. Ability to write clean, maintainable code and communicate technical decisions clearly. Nice to have Experience with geospatial or map-based interfaces such as Mapbox, MapLibre, or Turf. Experience with charting and visualization libraries such as Highcharts, D3, or Cytoscape. Experience with rich-text editors such as Lexical, Draft.js, or TinyMCE. Experience with drag-and-drop systems, real-time notifications, and internationalization. Experience working in a monorepo and maintaining shared frontend libraries. Familiarity with Sentry or comparable frontend observability tools. Experience planning and executing incremental migrations from legacy React patterns to modern React architecture.