Senior Frontend Engineer - Contractor

This position is listed on behalf of a partner company, who manages all applications and next steps. Our partner is looking for a Senior Frontend Engineer - Contractor based in Brazil.

You will join a product-driven engineering team focused on building modern, high-performance web applications that deliver seamless digital experiences at scale. In this role, you will take ownership of crafting responsive and intuitive user interfaces using React, working closely with product managers, designers, and backend engineers to turn ideas into production-ready features. You will contribute to shaping frontend architecture while ensuring scalability, performance, and maintainability across applications. The environment is highly collaborative, fast-paced, and quality-oriented, with a strong emphasis on clean code and user experience. Beyond feature delivery, you will play a key role in improving frontend standards, optimizing performance, and mentoring junior engineers. This is an opportunity to have real product impact while working with modern technologies in a globally distributed team.

You will be responsible for building and maintaining scalable, high-performance frontend applications while ensuring excellent user experience and technical quality across all web products. You will collaborate closely with cross-functional teams to translate requirements into intuitive interfaces and contribute to the continuous improvement of frontend architecture and practices.

• Develop, maintain, and optimize responsive web applications using React
• Translate product and design requirements into clean, functional, and intuitive UI components
• Ensure high performance, scalability, and cross-browser compatibility across applications
• Debug, troubleshoot, and resolve frontend issues to maintain a seamless user experience
• Integrate frontend applications with backend microservices and RESTful APIs
• Participate in code reviews and contribute to frontend engineering best practices
• Mentor junior engineers and support their technical growth through guidance and feedback
• Continuously improve frontend architecture, tooling, and development workflows

Requirements:

You bring strong experience in frontend engineering, particularly within modern JavaScript ecosystems, and are comfortable building complex, scalable web applications. You have a strong eye for detail, performance, and user experience, and you thrive in collaborative Agile teams.

• 5+ years of experience in frontend engineering with strong expertise in React
• Strong proficiency in JavaScript/TypeScript, HTML5, and CSS3
• Experience building responsive, cross-browser compatible web applications
• Solid experience integrating frontend applications with RESTful APIs
• Familiarity with testing frameworks such as Jest and React Testing Library
• Experience with frontend build tools (Webpack, Babel) and version control (Git)
• Understanding of accessibility standards (WCAG) and UI best practices
• Experience with frontend performance optimization techniques
• Experience working in Agile/Scrum environments
• Strong communication skills and ability to collaborate across distributed teams
• Ability to mentor and support junior engineers in a team setting

Benefits:

• Remote contractor opportunity based in Brazil
• Work on modern, scalable web applications with real product impact
• Collaborative, international engineering environment
• Exposure to product, design, and backend cross-functional teams
• Opportunity to mentor and grow within a senior technical role
• Work with modern frontend technologies and best practices
• Flexible collaboration structure suited for contractors
• Continuous learning and improvement culture