I am building a feature-rich auction site on SQL Server with a clean MVC architecture and need a developer who can deliver a fast, secure, mobile-responsive experience across three separate portals. Buyer Panel The bidder’s workspace must feel instantaneous. Real-time bidding is mandatory, with snapshots that refresh smoothly and an anti snipping safeguard to stop last-second steals. Buyers also need order tracking and clear, timely notifications for bid status so they never miss a win. Seller Panel Sellers must be able to upload lots, update shipping details as parcels move, and review sales analytics that surface their best-performing items and categories. Admin Panel I require granular moderation tools: approve or reject listings, suspend users, release funds, and step into any auction to resolve disputes. Core mechanics • Highest-bid-wins logic only—no penny bidding or gimmicks. • Shared, hardened authentication layer so one set of credentials works everywhere. • Integration with Razorpay plus manual/offline payment entry. • Full logging of bids, edits, payments, and admin actions for auditability. Tech expectations MVC pattern on the server, SQL Server for persistence, clean REST endpoints for future mobile apps, and responsive front-end templates that adapt flawlessly to phones, tablets, and desktops. Acceptance criteria 1. All three portals load under two seconds on 4G. 2. A fresh listing can pass from Seller → Buyer auction → Admin payout without any manual database tweaks. 3. Security tests show no SQL injection, XSS, or auth bypass vulnerabilities. 4. Codebase is handed over in a well-documented repo with build instructions. If you have delivered similar high-traffic auction or marketplace systems, let’s discuss your approach and timeline.