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rakuten

Senior UI Developer (1 Year Contract)

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Job Description:

This is a 1 year contract position

Rakuten Group, Inc. is a global leader in internet services and has a diverse ecosystem spanning across e-commerce, fintech, communications and more serving approximately 1.8 billion members worldwide. Founded in Tokyo in 1997, the Group operates in over 30 countries and regions with more than 30,000 employees.

Based in Singapore's Central Business District, Rakuten Asia Pte. Ltd. serves as the regional headquarters for Asia, driving value through areas such as advertising product development, product strategy, and data management to support Rakuten Group's global ecosystem.

Learn more at: https://global.rakuten.com/corp/

The Global Ad Technology Department (GATD) manages the whole of the advertising systems that power Rakuten. We are a cross-functional and data-driven organization working together in a diverse team spread across five countries: Japan, Singapore, India, China and UK.

GATD Website: https://corp.rakuten.co.jp/careers/feature/adtech/en/

We are looking for a highly skilled Senior UI Developer with strong expertise in React and TypeScript to design, develop, and maintain scalable, high-performance web applications. The ideal candidate should possess solid front-end architecture knowledge, experience integrating with backend services through REST APIs, and a strong understanding of testing practices and modern development workflows.

The candidate will collaborate closely with Product Managers, UX Designers, Backend Engineers, and Architects to deliver high-quality user experiences and contribute to the overall technical direction of the platform.

Responsibilities:

  • Design, develop, and maintain responsive and scalable web applications using React and TypeScript.

  • Translate UI/UX designs into clean, maintainable, and reusable code.

  • Integrate front-end applications with backend services using RESTful APIs.

  • Collaborate with backend teams to define API contracts and ensure seamless integration.

  • Design reusable UI components and shared libraries to improve development efficiency.

  • Participate in architecture discussions and contribute to front-end technology decisions.

  • Optimize application performance, accessibility, security, and responsiveness.

  • Write comprehensive unit, integration, and end-to-end tests.

  • Perform code reviews and mentor junior developers on best practices.

  • Troubleshoot and resolve production issues while ensuring system stability.

  • Work closely with DevOps and QA teams to support CI/CD pipelines and quality initiatives.

  • Contribute to Agile ceremonies including sprint planning, estimation, and retrospectives.

Requirements:

  • 5+ years of experience in front-end development.

  • Strong proficiency in JavaScript (ES6+) and TypeScript.

  • 3+ years of hands-on experience with React.

  • Experience with React Hooks, Context API, state management patterns, and component lifecycle.

  • Strong understanding of HTML5, CSS3, SCSS, and responsive design principles.

  • Experience with modern UI frameworks such as Material UI, Ant Design, or similar. ​

API Integration

  • Strong experience consuming and integrating REST APIs.

  • Experience handling authentication mechanisms such as JWT, OAuth, or SSO.

  • Knowledge of API error handling, retry mechanisms, caching, and performance optimization.

  • Ability to collaborate effectively with backend teams on API design and troubleshooting.

Front-End Architecture

  • Strong understanding of UI architecture patterns and scalable application design. • Experience designing modular and reusable component libraries.

  • Knowledge of Micro Frontend architecture is a plus. • Understanding of application security best practices and performance optimization techniques.

  • Familiarity with browser rendering, network optimization, and frontend performance monitoring.

Testing & Quality

  • Experience with testing frameworks such as:

  • Jest • React Testing Library • Cypress or Playwright

  • Experience implementing automated testing strategies and maintaining test coverage.

  • Familiarity with mocking APIs and integration testing approaches.

Development Practices

  • Experience with Git and modern branching strategies.

  • Familiarity with CI/CD pipelines and automated deployment processes.

  • Experience working in Agile/Scrum environments.

  • Strong debugging and problem-solving skills.

Rakuten is an equal opportunities employer and welcomes applications regardless of sex, marital status, ethnic origin, sexual orientation, religious belief or age.