Job Summary: We are seeking a Senior FullStack Developer passionate about designing, developing, and maintaining robust and scalable web applications, leading technical initiatives, and collaborating with multidisciplinary teams to deliver high-quality products. Key Highlights: 1. Design and develop high-quality full-stack web applications. 2. Lead technical architecture and propose innovative solutions. 3. Collaborate with multidisciplinary teams to deliver features. Join Stefanini! At Stefanini, we are more than 30\.000 geniuses connected from 41 countries, doing what they love and co\-creating a better future. You definitely don’t want to miss this! Why will we choose you? Because the challenges you’ll take on reflect your ambitions! **Responsibilities and Duties** * The Senior FullStack Developer will be responsible for designing, developing, and maintaining robust and scalable web applications, working both on the frontend and backend. This role requires advanced experience in modern web development technologies, especially the JavaScript stack (Express JS for backend, React JS and Next JS for frontend). The ideal candidate must be capable of leading technical initiatives, proposing innovative solutions, and closely collaborating with multidisciplinary teams to deliver high-quality products aligned with business objectives. * 3–5 years of proven experience as a FullStack Developer, with at least 3 years working with Express JS, React JS, and Next JS in production projects. * Design, develop, and maintain high-quality full-stack web applications. * Lead the technical architecture of new projects and propose improvements to existing ones. * Collaborate with designers, product owners, and other developers to define and deliver features. * Ensure code quality through reviews, testing, and sound development practices. * Document technical solutions and relevant processes for the team. * Research and adopt new technologies that add value to the product and the team. * Actively participate in agile ceremonies and contribute to the team’s continuous improvement. **Requirements and Qualifications** * University degree in Systems Engineering, Computer Science, or related fields. * Certifications in web development, JavaScript frameworks, or advanced courses in related technologies are valued. * Advanced proficiency in JavaScript (ES6\+), both frontend and backend. * Solid experience developing RESTful APIs using Express JS. * Extensive experience with React JS for building dynamic and reusable user interfaces. * Experience developing SSR and SSG applications using Next JS. * Knowledge of relational and non-relational databases (e.g., MongoDB, PostgreSQL). * Experience with version control tools such as Git. * Familiarity with agile methodologies (Scrum/Kanban). * Knowledge of unit and integration testing (Jest, Mocha, etc.). * Experience deploying applications to the cloud (AWS, Azure, Vercel, etc.) is a plus. * Excellent communication and teamwork skills. * Technical leadership ability and mentorship of less-experienced developers. * Proactivity and problem-solving orientation. * Adaptability to change and continuous learning. * Ability to manage priorities and work under pressure in dynamic environments. **Additional Information** Are you looking for a place where your ideas shine? With over 38 years of experience and a global presence, at Stefanini we transform tomorrow—together. Here, every action counts and every idea can make a difference. Join a team that values innovation, respect, and commitment. If you are a disruptive individual, committed to continuous learning, and innovation is in your DNA, then we’re exactly what you’re looking for. Come and let’s build a better future—together!