Modern full-stack multi-vendor e-commerce platform built using Next.js, Node.js, Express.js, and MongoDB with scalable marketplace architecture for customers, vendors, and admin management. Features include secure authentication with Google OAuth, Razorpay payment integration, dynamic product search and filtering, vendor dashboards, Cloudinary-based media management, responsive mobile-first UI, and production-ready deployment using Vercel and Railway. Designed with focus on real-world marketplace workflows, scalability, and modern web application practices.