How AlphaAuctions Keeps Every Bidder in Sync in Real Time

AlphaAuctions is a real-time online auction and bidding platform I built with Next.js, TypeScript, Prisma, PostgreSQL, and Socket.io. The core technical problem is deceptively simple to state and easy to get wrong: every bidder watching a listing needs to see the same current price and time remaining, at the same moment, with no polling lag.

Why polling wasn't good enough

The obvious naive approach — poll an API every few seconds for the current price — creates a credibility problem for an auction. If a bidder's screen is even a couple of seconds stale, they can believe they're winning a listing they've already lost, or hesitate on a bid because the countdown they're looking at doesn't match reality.

AlphaAuctions uses Socket.io to push bid updates, price changes, and countdown state to every client in a bidding room the instant they happen, instead of clients pulling for updates on a timer.

Durable state underneath the real-time layer

Real-time transport handles what bidders see, but the actual bid history, current price, and listing state need to survive disconnects and stay consistent under concurrent bids. That's Prisma over PostgreSQL — a relational, type-safe data layer underneath the WebSocket layer, so a page refresh or a dropped connection doesn't lose or corrupt state.

Real-time doesn't have to mean slow

A common assumption is that shipping a live, socket-driven interface means trading away initial page performance. Running Lighthouse against the production site says otherwise: a perfect 100 performance score, 1.4s Largest Contentful Paint, and zero cumulative layout shift, despite the page establishing a WebSocket connection and rendering a live price chart on load.

The main lever for that: being deliberate about what needs to be ready before first paint versus what can initialize just after. The socket connection and chart don't block the initial render — they attach once the page is already visually complete.