Middle Fullstack developer for Lebara (Node.js, Next.js) (#4491)

N-iX is looking for a talented Middle Fullstack engineer to join our team!  

Our client is one of Europe's fastest-growing mobile companies with over 5  million active customers, 1,000 employees worldwide, and operations in five countries. The client is using the mobile virtual network operator business model. 

We are seeking a skilled Full Stack Developer with expertise in Next.js and Node.js to design, develop, and maintain modern, scalable web applications. The ideal candidate will have strong proficiency in both frontend and backend technologies, experience in building performant applications, and a good understanding of DevOps practices.

Responsibilities:

• Design, develop, and maintain scalable web applications using Next.js (React framework) and Node.js
• Build and optimize server-side rendering (SSR) and static site generation (SSG) with Next.js
• Develop and maintain RESTful APIs or GraphQL APIs using Node.js and related frameworks (Express, Nest.js, etc.).
• Implement authentication, authorization, and secure data handling practices
• Collaborate with UI/UX designers to create responsive, accessible, and user-friendly interfaces
• Optimize application performance (caching, code-splitting, lazy loading, CDN usage)
• Work with databases (SQL or NoSQL) for schema design, queries, and data modeling
• Integrate third-party services, APIs, and microservices
• Write clean, maintainable, and well-tested code
• Participate in code reviews, design discussions, and Agile/Scrum processes
• Deploy and monitor applications using cloud services (AWS, GCP, Azure) or platforms like Vercel

Requirements:

• 3+ years of professional experience with Next.js and Node.js
• Strong experience in JavaScript (ES6+) and TypeScript
• Hands-on experience with Next.js (SSR, SSG, API routes, dynamic routing)
• Solid experience with Node.js and backend frameworks (Express.js, Nest.js)
• Good understanding of React ecosystem (hooks, context API, state management libraries like Redux/Zustand)
• Experience with databases (PostgreSQL, MySQL, MongoDB, or similar)
• Familiarity with RESTful APIs and GraphQL
• Knowledge of CI/CD pipelines, Git, and containerization (Docker/Kubernetes)
• Strong debugging and problem-solving skills
• Good understanding of web security best practices (JWT, OAuth, CSRF, XSS, etc.)

Would be a plus:

• Experience deploying applications on Vercel, AWS Lambda, or other serverless platforms
• Familiarity with Headless CMS (e.g., Strapi, Sanity, Contentful)
• Experience with testing frameworks (Jest, Cypress, Playwright)
• Knowledge of microservices and event-driven architectures
• Familiarity with WebSockets and real-time communication

Experience with performance optimization and SEO best practices for Next.js apps