Staff Engineer / React UI 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 strong engineering culture, modern technologies, and deep domain expertise to deliver scalable and reliable trading experiences

Responsibilities

Position Purpose

We are seeking a React UI Developer (Mid‑Level) to contribute to the development of our next‑generation web trading platforms. This role focuses on building high‑quality, performant, and maintainable frontend features using React and TypeScript, working closely with senior frontend engineers, backend teams, designers, and product managers.

You will contribute to reusable UI components, follow established frontend architecture and standards, and help deliver highly interactive, real‑time user experiences.

Primary Responsibilities

Frontend Architecture & Development

Web Trading Platforms

• Develop responsive, high‑quality web trading applications using React and TypeScript
• Implement UI features following established frontend architecture and standards
• Ensure consistent user experience across modern browsers and devices
• Collaborate with senior engineers to deliver scalable and maintainable solutions

Component & Design System Development

• Build and enhance reusable UI components within an existing design system
• Apply design tokens, UI primitives, and accessibility standards consistently
• Follow best practices for component composition, testing, and maintainability
• Contribute improvements and fixes to shared component libraries

State Management & Routing

• Implement client‑side state management using approved libraries and patterns
• Work with existing routing solutions for complex, multi‑feature applications
• Understand data flow, component lifecycle, and state‑driven UI behavior

Performance & Reliability

Performance Optimization

• Apply performance best practices such as memoization, lazy loading, and code splitting
• Optimize rendering behavior for data‑heavy and interactive UI components
• Identify and resolve UI performance issues with guidance from senior engineers

Error Handling & Observability

• Implement basic error handling patterns, including error boundaries
• Add logging and monitoring hooks according to team standards
• Help improve frontend stability and debuggability through proactive fixes

Security & Integration

Authentication Integration

• Integrate frontend applications with existing authentication and identity solutions
• Follow secure patterns for handling sessions, tokens, and authenticated flows
• Adhere to security and compliance requirements defined by platform teams

API Integration

• Consume RESTful APIs and real‑time data streams efficiently
• Handle loading states, error conditions, and partial data scenarios gracefully
• Collaborate with backend engineers to clarify API usage and constraints

Collaboration

Cross‑Functional Collaboration

• Work closely with product managers, designers, backend engineers, and QA teams
• Translate UX and business requirements into frontend implementations
• Participate actively in sprint planning, refinement, and reviews

Team Contribution

• Participate in code reviews to maintain code quality and consistency
• Communicate progress, risks, and technical questions clearly
• Continuously improve frontend skills and understanding of the product domain

Required Qualifications

To succeed in this role, you will need:

• 2–4 years of professional frontend development experience
• Strong knowledge of JavaScript and TypeScript (ES6 , async programming)
• Hands‑on experience with React, including:
• Functional components and hooks
• Component composition and reuse
• Basic performance optimization techniques
• Experience with client‑side state management and routing solutions
• Solid understanding of RESTful APIs and frontend‑backend integration
• Familiarity with frontend testing, debugging, and code review practices

Qualifications

What Will Make You Stand Out

• Experience working on data‑intensive or real‑time web applications
• Familiarity with design systems and reusable component libraries
• Exposure to financial, trading, or regulated environments
• Experience with frontend build tooling and CI/CD pipelines
• Strong attention to UI quality, performance, and user experience

Education

• Bachelor’s or Master’s degree in Computer Science, Engineering, or a related field(or equivalent practical experience)

Working Environment

• Hybrid