React Developer (Whippany)

React Web Developer — American Express One App

Location: Phoenix, AZ - Locals only

Openings: 6 positions

Mandatory Experience: Front-end React development with hands-on American Express One App experience

Interview Mode: In-person

Job Summary

We are seeking React Web Developers with hands-on American Express One App experience to develop and maintain responsive, reusable front-end applications. The role involves building user interfaces, integrating APIs, improving application performance, and collaborating with product, design, back-end, and QA teams. Candidates must be comfortable delivering features within an existing One App application environment.

Key Responsibilities

• Develop and maintain responsive web interfaces using React, JavaScript, HTML, and CSS.
• Build reusable components and implement features within the American Express One App environment.
• Develop and maintain modular front-end features using One App’s Holocron module architecture.
• Integrate REST APIs and handle application state, loading states, validation, and errors.
• Collaborate with designers and product teams to translate requirements into accessible, consistent user experiences.
• Optimise rendering, page-load performance, and front-end resource usage.
• Write and maintain unit and integration tests and support regression testing.
• Investigate browser, application, and integration issues and implement fixes.
• Participate in code reviews and follow established coding, security, and quality standards.
• Work with back-end engineers, QA, and DevOps teams to support integration and deployment.
• Document components, implementation decisions, and development workflows.

Required Qualifications

• Hands-on experience developing front-end applications with React.
• Prior hands-on experience with American Express One App is required.
• Strong JavaScript, HTML, CSS, responsive design, and browser-debugging skills.
• Understanding of One App’s modular architecture and independently developed, tested, and deployed Holocron modules.
• Experience integrating REST APIs and working with JSON.
• Experience with React component patterns, state management, and front-end testing.
• Familiarity with Git, code reviews, and CI/CD workflows.
• Ability to troubleshoot front-end issues and collaborate effectively across engineering and product teams.