**Company description** **Publicis Sapient** As a **Senior Fullstack Engineer** at Publicis Sapient, you will work with some of today’s top brands and take ownership of designing, developing, and implementing robust and scalable applications. These solutions will transform massive datasets into intuitive, high-impact experiences, ranging from e-commerce platforms to advanced data-driven visualizations. You will combine your frontend and backend development skills to deliver end-to-end solutions, ensure code quality, lead pull request reviews, and mentor junior developers. **Responsibilities** **Your Impact** + **Develop end-to-end solutions** : Implement complex features across the frontend and backend, leveraging React to build dynamic user interfaces and Node.js with GraphQL to create efficient, modern backend services. + **Ensure quality and testing** : Write and execute unit and integration tests to validate both frontend and backend code, ensuring continuous integration and automated testing processes are in place. + **Lead best practices** : Act as a role model for the team by adopting methodologies such as TDD, clean architecture, and development best practices. Evaluate and test new tools and frameworks to deliver value to the team and clients. + **Mentorship and collaboration** : Support the technical growth of junior developers and foster a culture of shared learning through webinars, technical talks, and knowledge-sharing sessions. **Optimization and performance** : Design scalable and optimized applications tailored for diverse environments and network conditions, ensuring a balance between performance **Qualifications** **Skills & Experience** + Strong expertise in frontend development with **React** (including React Hooks and Redux). + Experience in backend development with **Node.js** and building scalable APIs using **GraphQL** . + Deep knowledge of **HTML5** , **CSS3** , **JavaScript** , and component-based architecture. + Familiarity with modern tools like Webpack, Babel, and Node.js packages to build complex applications. + Experience working with databases (SQL or NoSQL) and basic server configurations. + Ability to lead small teams and mentor junior developers. + Expertise in designing systems optimized for SEO and accessibility. + Understanding of networking considerations (TCP/IP), performance optimization, and browser rendering.