We are seeking an experienced Senior Front-End Developer to play a critical role in shaping the next generation of StoneX’s global web platform. As part of our Websites Development team, you will help drive the evolution of our client-facing marketing ecosystem — built on modern, decoupled technologies including Kontent.ai (headless CMS) and Uniform (DXP/frontend orchestration).

 You will ensure the seamless delivery of high-performing, scalable, and visually compelling web experiences used by clients around the world. While working at the intersection of legacy platform support and forward-looking innovation, helping guide our transition to a modern composable architecture. We’re looking for someone who thrives in dynamic environments, takes ownership, and is energized by building quality into every stage of development.

Key Responsibilities

• Own quality across a modern web ecosystem
  Lead efforts across our composable CMS platform (Kontent.ai + Uniform), ensuring high-quality releases that deliver exceptional user experiences across global marketing sites.
• Drive strategy in an Agile, distributed team
  Collaborate daily within a globally distributed Scrum team spanning the U.S., London, Kraków, Bangalore, and Bogotá — contributing to sprint planning, estimation, test design, and release execution.
• Partner cross-functionally to elevate delivery
  Work closely with Product, Marketing, Design, and Engineering to translate business requirements into robust, testable solutions. Ensure features are clearly defined, testable, and aligned with user expectations.
• Champion AI and quality engineering best practices
  Identify opportunities to expand use of AI in coding review, deployments, and improve efficiency, ensuring quality is embedded early in the development lifecycle.
• Support platform evolution and migration
  Play a key role in maintaining legacy systems while actively contributing to the migration toward a modern, headless architecture. Help identify risks, gaps, and opportunities throughout the transition.
• Ensure performance and scalability standards
  Validate that all site components meet modern performance benchmarks, including Core Web Vitals, ensuring fast, accessible, and reliable user experiences.
• Deliver end-to-end ownership of quality
  Take responsibility for features from concept through release — troubleshooting complex issues, driving timely resolutions, and ensuring adherence to development standards and best practices.
• Contribute to a culture of excellence and continuous improvement
  Actively mentor, collaborate, and elevate team standards. Stay current with tools, frameworks, and industry trends, bringing new ideas to strengthen our engineering capabilities.

To land this role, you will need:

• 5+ years of experience in web application development
• Strong proficiency in Next.js, React, and TypeScript.
• Basic understanding of Core Web Vitals (LCP, FID, CLS), performance metrics, and how to improve them for better user experience.
• Expertise in HTML5, JavaScript (ES6+), CSS, and one of the following pre-processors: SCSS, SASS, LESS (CSS preprocessors).
• Experience working with Bootstrap or Tailwind CSS (Utility-first CSS framework).
• Experience working with RESTful APIs and third-party integrations.
• Proficiency with Git (Bitbucket or GitHub) and CI/CD workflows/actions.
• Experience with unit testing frameworks (e.g., Jest, React Testing Library).
• Familiarity with Storybook for UI component development.
• Experience working in a monorepo environment.
• Familiarity with build tools like Webpack, Vite, or Turborepo.
• Experience working in agile environment (Scrum, Kanban).
• Basic understanding of accessibility standards (WCAG) and how to implement accessible web applications.

Nice to Have:

• Experience woking with server-side rendering (SSR), static site generation (SSG), and Incremental Static Regeneration (ISR) use cases in Next.js.
• Knowledge of SEO best practices for modern web applications and how to implement SEO-friendly features (e.g. meta tags, structured data, schema, and SEO optimization for performance).
• Basic understanding of security concepts like API authentication/authorization, encryption, and Windows certificates.
• Familiarity with headless CMSs (e.g., Kontent.AI).

What Makes You Stand Out:

• Passion for building scalable, high-performance web components.
• Deep understanding of modern web development and headless CMS trends and best practices.
• Experience working on highly trafficked global websites.
• Strong debugging and problem-solving skills.
• Excellent verbal and written communication skills in English.