A Node.js Developer with 4 years of experience is responsible for designing, building, and maintaining scalable server-side applications, APIs, and microservices. Key duties include optimizing database performance (SQL/NoSQL), implementing robust security, and mentoring junior developers. This role requires advanced JavaScript proficiency, expertise in Express.js, and cloud experience (AWS/GCP). Key Responsibilities (4+ Years Experience) Backend Development: Architect, develop, and deploy high-performance, scalable back-end services using Node.js and Express.js. API Design: Design, build, and maintain secure RESTful APIs. Database Management: Proficiently handle database schema design, optimization, and management, including MongoDB, MySQL, or PostgreSQL. System Architecture: Participate in architectural decisions to ensure application performance, reliability, and security. Code Quality & Optimization: Write clean, modular, and maintainable code, performing code reviews to ensure high-quality standards. Cloud & Deployment: Deploy applications using CI/CD pipelines and manage cloud infrastructure (e.g., AWS, GCP). Troubleshooting: Diagnose and resolve complex performance bottlenecks and production issues. Collaboration: Work in Agile teams with front-end developers, product managers, and designers to integrate user-facing elements. Required Qualifications & Skills Experience: 3-5 years of professional experience in back-end development specifically with Node.js. Technical Skills: Deep knowledge of JavaScript (ES6+), Node.js, and frameworks like Express.js. Databases: Strong proficiency in NoSQL (MongoDB) and SQL (MySQL/PostgreSQL) databases. API & Tools: Experience with RESTful services, WebSocket, Git, and third-party API integrations. Testing: Experience with unit and integration testing frameworks (e.g., Jest, Mocha). Education: Bachelor’s degree in Computer Science or a related field. Preferred Qualifications Experience with microservices architecture and containerization (Docker, Kubernetes). Experience with caching mechanisms (Redis). Knowledge of frontend frameworks like React or Angular.