Senior Frontend Software Engineer – React / TypeScript / Next.js

We are looking for an experienced Senior Frontend Software Engineer to help build a modern, scalable, high-performance web application for a business-focused financial technology platform. The ideal freelancer has strong experience building production-grade frontend applications with React and TypeScript, excellent UI/UX instincts, and experience working closely with product managers, designers, and backend engineers. What You’ll Do * Design, develop, and maintain modern web applications using React and TypeScript * Build scalable, responsive, accessible, and reusable frontend architectures * Develop dashboards, dynamic forms, and data-driven user interfaces * Work with product and UX teams to translate requirements into polished user experiences * Integrate frontend applications with backend APIs * Build and maintain reusable component libraries and design-system components * Optimize applications for performance, scalability, reliability, and cross-browser compatibility * Implement analytics, monitoring, instrumentation, and frontend observability * Participate in technical architecture discussions, RFCs, and proof-of-concept development * Establish strong coding, testing, and frontend engineering standards * Write unit, integration, component, and end-to-end tests * Participate in code reviews and mentor other developers when needed * Work independently to plan tasks, identify technical risks, and deliver milestones on schedule Required Skills Frontend * React * TypeScript * Next.js * React 19 / modern React architecture * Responsive and accessible UI development * Component-based architecture State & Data * TanStack Query / React Query * Zustand * Experience with type-safe API/client-server communication * REST and/or GraphQL API integration UI & Design * Tailwind CSS * Component libraries / design systems * Strong attention to visual details and pixel-perfect implementation * Experience with animations such as Framer Motion or similar libraries Architecture & Development * Turborepo / monorepo architecture * Scalable frontend architecture * Performance optimization * Cross-browser compatibility * Accessibility * Clean, maintainable, production-quality code Testing & DevOps * Vitest * Unit and integration testing * Familiarity with component and end-to-end testing * GitHub Actions / CI/CD * Git and modern development workflows Monitoring & Analytics Experience with tools such as: * Datadog RUM / APM * Amplitude * FullStory * Other frontend analytics and observability platforms React Native Experience with React Native / Expo is a strong plus, particularly if you have worked on applications sharing code or architecture between web and mobile platforms. Requirements * 3+ years of professional software engineering experience * Strong frontend engineering background * Expert-level React and TypeScript knowledge * Experience building production applications * Strong understanding of frontend architecture and design patterns * Excellent communication skills * Ability to work independently and collaborate with product, UX, and backend teams * Strong problem-solving and debugging skills * Ability to provide clean, well-tested, maintainable code Project Expectations We are looking for someone who can contribute at a senior engineering level, not simply complete isolated frontend tickets. You should be comfortable taking a feature from: Requirements → Architecture → UI implementation → API integration → Testing → Performance optimization → Production delivery We value engineers who can identify problems proactively, suggest better technical approaches, and contribute to the overall product architecture. Engagement * Experience level: Expert * Project type: Long-term / ongoing * Work: Remote * Hours: Flexible, with some overlap with U.S. Eastern Time preferred * Potential: Long-term collaboration for the right freelancer To Apply Please include: 1. A brief introduction about your frontend engineering experience. 2. Years of professional experience with React and TypeScript. 3. Examples of production applications you have built. 4. Your experience with Next.js and React 19. 5. Your experience with state management such as Zustand and TanStack Query. 6. Your experience with monorepos/Turborepo. 7. Links to your GitHub, portfolio, or relevant projects. 8. Your preferred hourly rate. 9. Your availability and typical weekly capacity. Please also answer: What is the most technically challenging React/TypeScript application you have built, and what architectural decisions did you make to keep it scalable and maintainable?