Senior Full-Stack Developer ( React.js/Next.js/Node.js ) for Booking & Appointment Module

We're looking for an experienced Full-Stack Developer to build the Booking & Appointment Management module for our existing AI-powered SaaS platform. Our platform, branding, core infrastructure, and product vision are already established. You can explore the existing platform and features on our website to understand the product before applying. This project is not for building an entire SaaS product from scratch. Your responsibility will be to design and develop a production-ready booking module that integrates seamlessly with our existing system. The module should include appointment scheduling, calendar management, staff availability, customer bookings, automated reminders, payment integration, and an owner dashboard for managing appointments and business operations. The ideal developer should have strong experience with React or Next.js for the frontend, Node.js, NestJS, or Python (FastAPI) for the backend, and PostgreSQL or MongoDB for database design. Experience with REST APIs, role-based access control, authentication, payment gateways, WhatsApp/SMS notifications, cloud deployment, and scalable SaaS architecture is highly preferred. If you've previously built booking systems, scheduling platforms, or SaaS modules that integrate into existing products, we'd love to hear from you.