Senior Web Developer

Overview Connecting clients to markets – and talent to opportunity With 4,300 employees and over 400,000 retail and institutional clients across more than 80 offices on five continents, StoneX is a Fortune-100, Nasdaq-listed provider connecting clients to the global markets. We focus on innovation, human connection, and delivering world-class products and services to investors worldwide. At StoneX, you’ll join an institutional-grade financial services organization building modern, high-performance digital platforms.

Our teams combine cutting-edge technology, deep domain expertise, and strong engineering culture to deliver scalable and reliable trading experiences. Responsibilities Position Purpose We are seeking a Senior React UI Developer to design and build our next-generation web trading platforms . This role focuses on frontend architecture, performance optimization, and scalable UI development , working closely with backend, mobile, and platform teams.

You will play a key role in shaping UI standards, reusable component systems, and frontend best practices for highly interactive, real-time trading applications. Primary Responsibilities Frontend Architecture & Development Web Trading Platforms Design and develop responsive, high-performance web trading applications using React and TypeScript Ensure consistent user experiences across browsers and devices Component & Design System Development Build and maintain reusable UI components and composite componentsEnforce consistent usage of design tokens and UI primitivesPromote best practices for component composition, accessibility, and maintainability State Management & Routing Design scalable client-side state management strategiesImplement robust routing architectures for complex, multi-domain applications Performance & Reliability Performance Optimization Implement lazy loading, code splitting, and bundle optimization strategiesOptimize rendering performance for real-time and data-heavy UIs Error Handling & Observability Implement error boundaries, logging, and monitoring for frontend applicationsImprove resiliency and debuggability of UI systems Security & Integration Authentication Integration Integrate frontend applications with IDP-based authentication systems Ensure secure handling of sessions, tokens, and user identity flows API Integration Consume RESTful APIs and event-driven data streams efficientlyCollaborate with backend teams to define frontend-friendly API contracts Collaboration & Leadership Cross-Functional Collaboration Work closely with product managers, designers, backend engineers, and QA teamsTranslate business and UX requirements into scalable frontend solutions Technical Leadership Mentor junior and mid-level developersDrive frontend best practices, architectural consistency, and code quality Stakeholder Communication Clearly communicate technical decisions, trade-offs, and implementation approaches Qualifications Required Qualifications To succeed in this role, you will need: 5+ years of professional frontend development experience Expert knowledge of JavaScript and TypeScript (ES6+, async programming, closures, types) Strong experience with React , including:Hooks and component patternsLazy loading and code splittingError boundaries and error capturingState management librariesRouting architectures Strong understanding of frontend performance optimization techniques Experience integrating with authentication and authorization systems Solid understanding of RESTful APIs and frontend-backend integration What Will Make You Stand Out Experience building trading, financial, or real-time data platforms Familiarity with React Native or shared web/mobile UI strategies Experience working within large-scale design systems Understanding of CI/CD pipelines and frontend build tooling Experience working in regulated or security-sensitive environments Education Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field (or equivalent practical experience) Working Environment Hybrid