Architected and maintained modular microservices with REST and GraphQL APIs. Implemented secure authentication and authorization flows using JWT with role-based access control. Built CI/CD pipelines using GitHub Actions and Docker to enable automated testing and deployment. Collaborated with designers and product managers to enhance SEO and user experience using Next.js server-side rendering. Implemented unit and integration tests using Mocha and Joi for validation. Built RESTful APIs and real-time features using Socket.IO and WebSockets for live updates and notifications. Enforced code quality with ESLint and maintained high-quality tests with Mocha.