Marketplace · Online auctions
PromoHub
Private auctions by link: sell a car, an apartment or a lease to the buyers you invite — and let them compete on price.
- Status
- Live
- Year
- 2026
- What we delivered
- Product design · Web app · Backend & API · Security audit · SEO · DevOps
- pre-launch audits: security, UX, SEO
- 3
- pre-launch audits: security, UX, SEO
- is all a seller needs to share
- 1 link
- is all a seller needs to share
- contacts shown to anyone but the owner and the winner
- 0
- contacts shown to anyone but the owner and the winner
The challenge
When someone sells a car or rents out an apartment, offers arrive in dozens of separate messenger chats. The seller negotiates with each buyer one by one, nobody sees the competition, and the real market price stays a guess.
Public marketplaces solve discovery, not this: the seller already has an audience and wants a fair, transparent way to let those specific people bid — without exposing the lot or their contacts to the whole internet.
The solution
PromoHub turns that chaos into a simple auction. The owner creates a lot with photos, a starting price, a bid step and an end time, and shares one short link in Telegram, Viber, Facebook or anywhere else — the link unfurls into a rich preview with the lot's photo and title.
Buyers register, confirm their email and bid online, seeing the current price and the full bid history. When the auction ends, the system picks the winner and emails the owner and the winner each other's contact details — and nobody else ever sees them.
Key capabilities
- 01
Race-free bidding
Each bid locks the auction in a database transaction and updates the price atomically — two simultaneous bids can never both win.
- 02
Private by link
Unguessable lot IDs, masked bidder names, and contacts revealed only to the owner–winner pair after the end.
- 03
Shareable everywhere
Short /a/… links with per-lot Open Graph previews in Telegram, Viber and Facebook.
- 04
Automatic closing
Auctions close on time on their own; the winner and the owner are notified by email.
- 05
Hardened for production
Rate limits, session invalidation on password change, no email enumeration, image-content validation, least-privilege storage access.
- 06
One-push deploys
CI/CD builds and ships containers behind Caddy with automatic HTTPS and database migrations on every release.
Screens
The result
PromoHub is live at promohub.dovbeta.com. Before going public it passed a full security, UX and SEO audit.
Sellers get a fair market price set by real competing bids instead of private haggling, and buyers get a transparent process with every bid on record.
Technology
- React
- Vite
- Node.js
- Express
- PostgreSQL
- MinIO
- Podman
- Caddy
- GitHub Actions
Want something like this for your business?
Tell us about your idea or the process you want to automate. We'll propose a solution, a timeline and the first working version.
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