Job Summary: We are looking for a Mid-Level Web Developer with solid experience in React.js and Next.js to develop modern, scalable, and high-performance applications, collaborating with multidisciplinary teams. Key Highlights: 1. Develop modern, high-performance, and responsive interfaces with React and Next.js 2. Participate in front-end architecture decisions and propose scalable solutions 3. Join a highly technical team and collaborate across multiple areas **Job Description:** We are seeking a **Mid-Level Web Developer** with solid experience in **React.js** and **Next.js**, developing modern, scalable, and high-performance applications. The ideal candidate for this position has mastery of core JavaScript ecosystem technologies, strong front-end architectural capability, sound engineering practices, and proven experience in complex projects. You will join a highly technical team and collaborate with product, UX/UI, and backend teams to deliver robust, reusable solutions aligned with industry best practices. **Responsibilities** * Develop modern, high-performance, and responsive interfaces using **React** and **Next.js** * Participate in front-end architecture decisions, proposing scalable technical solutions * Create reusable and well-documented components following best practices * Work with SSR, SSG, and advanced Next.js optimizations * Maintain clean, testable, and well-structured code * Collaborate with multidisciplinary teams (product, UX, backend) * Conduct code reviews and mentor junior and mid-level developers * Ensure high application quality, security, and performance * Participate in sprint planning and contribute technical estimates **Required Qualifications** * Solid experience with **React.js** * Advanced experience with **Next.js** (SSR, SSG, ISR, performance optimizations) * Proficiency in **JavaScript** and **TypeScript** * Experience with **CSS Modules, Styled Components, and Tailwind** * Consumption of REST or GraphQL APIs * Knowledge of testing frameworks (Jest, React Testing Library, or similar) * Experience with version control tools (Git) * Mastery of best practices: Clean Code, SOLID, accessibility, performance * Proven experience in large-scale or highly complex projects **Nice-to-Have (not required)** * Experience with **Liferay** (DXP, Portal, front-end modules) * Knowledge of containers (Docker) * Experience with CI/CD (GitHub Actions, GitLab CI, Jenkins, etc.) * Experience with micro frontends * Familiarity with Agile / Scrum * Experience with cloud platforms (AWS, GCP, or Azure) **Job Information** * PJ contract. **Location****Contract Model** São Paulo, SP, BR Freelance PJ