Senior Frontend Developer ReactJS / NextJS

Job Title: Senior UI Developer - ReactJS / Next.js / TypeScript Location: Sao Paulo, Brazil (Hybrid) Experience Level: 10+ Years (Mid-Senior Level) Employment Type: Contract We are seeking a highly skilled and experienced Senior UI Developer with a strong background in ReactJS, Next.js, TypeScript, and Unit Testing.

The ideal candidate will have a proven track record of building scalable, responsive, and high-performance web applications.

This role requires a collaborative mindset, attention to detail, and the ability to lead UI development initiatives from concept through execution.

Key Responsibilities: Develop and maintain modern, scalable front-end applications using ReactJS and Next.js.

Write clean, efficient, and well-documented code using TypeScript.

Implement unit testing frameworks (e.g., Jest, React Testing Library) to ensure robust code quality.

Optimize application performance, scalability, and user experience.

Collaborate with UX/UI designers, backend developers, and product owners to deliver seamless user experiences.

Review and mentor the work of junior developers to ensure adherence to best practices and coding standards.

Participate in code reviews, architectural discussions, and agile ceremonies (e.g., sprint planning, retrospectives).

Stay current with front-end technologies and trends to drive innovation and best practices within the team.

Required Skills and Qualifications: 10+ years of overall software development experience.

Strong expertise in ReactJS and Next.js frameworks.

Proficient in TypeScript and modern JavaScript (ES6+).

Hands-on experience with unit testing tools and frameworks (e.g., Jest, Mocha, Cypress).

Strong understanding of HTML5, CSS3, SASS/SCSS, and responsive web design.

Familiarity with state management libraries such as Redux, Zustand, or Recoil.

Experience with RESTful APIs, GraphQL, and client-server integration.

Knowledge of CI/CD pipelines and version control systems (e.g., Git, GitHub, GitLab).

Excellent problem-solving skills and attention to detail.

Strong communication and collaboration skills.

Education: Bachelor's or master's degree in computer science, Engineering, or a related field.