Full Stack MERN Developer for Existing SaaS Application (Enhancements, Features & API Integrations)

Job Description: We are looking for an experienced Full Stack MERN Developer to work on an existing SaaS application to enhance the application by adding new features, improving existing functionality, integrating third-party APIs, fixing bugs, and optimizing performance. The ideal candidate should have strong experience with React.js, Node.js, Express.js / Nest.js, PostgreSQL, and building scalable SaaS applications. Candidate should must knows: * Understand and work with an existing MERN codebase. * Develop new features and improve existing functionality. * Build and maintain responsive React.js frontend components. * Develop and optimize backend services using Node.js and Express.js / Nest.js. * Design, maintain, and optimize PostgreSQL databases. * Integrate third-party APIs such as payment gateways, authentication and other external services. * Build and maintain secure REST APIs. * Implement authentication and authorization (JWT/OAuth). * Debug issues, fix bugs, and improve application performance. * Write clean, maintainable, and well-documented code. * Collaborate with the team to deliver high-quality features.