Bidnest case study

Confidential (student housing marketplace) · Property technology

A bidding-based marketplace for off-campus rentals. Live updates are scoped per listing, so 1,000+ people can bid at once.

Client project, name changed on request

Every screen receives only the bids it is watching.

Real-time subscriptions are scoped per listing, so a client never processes updates for listings it is not looking at. Bid order is decided once, in a serialised server-side transaction, and clients reconcile to the committed result. The platform holds 1,000+ concurrent bidders with updates in 200 ms.

What keeps it lean

01Subscriptions scoped per listing
02One authoritative decision on the server
03Access enforced by row-level security

Each request, user or agent gets the data it needs and nothing more.

The challenge

Student housing is dominated by fixed-price listings with no room to negotiate, scattered across platforms nobody trusts. Parents pay for most of these rentals and have no way into the process at all. The market needed a place where the price could be found openly, where every bidder saw the same number, and where a parent could act on a student’s behalf.

The work

We designed and built a live bidding marketplace over WebSockets, with bid acceptance serialised on the server so there is one authoritative order, and real-time subscriptions scoped per listing so each screen receives only the bids it is watching. Students, parents and landlords each got a dashboard built for their role, with messaging, service booking and notifications on top.

Inside the product

More than one screen.

The product name and data have been changed at the client's request; these screens recreate Bidnest as it was built.

Listing and live bid

Bid history updates in under 200 ms, with a parent co-signer on the bid.

Student dashboard

Active bids, lease progress and services booked from partners.

Messaging

Students, landlords and providers in one thread, with bookings on the record.

On the phone

Home

Listing and live bid

Student dashboard

Messaging

How it is built

Architecture

Next.js over Supabase and PostgreSQL. Bids flow through a WebSocket channel and are validated server-side before commit, so a client can never post a winning bid it did not earn. Role access is enforced by row-level security.

Key features

Bidding marketplace for verified off-campus rentals

Parent access to bid and message on a student’s behalf

Service booking for moving, cleaning and repairs

Built-in messaging between students, landlords and providers

In-app, email and SMS notifications

Listings filtered by proximity to partner schools

Challenges & solutions

Challenge

Simultaneous bids on the same listing raced each other and could both be accepted.

Solution

Moved bid acceptance into a serialised server-side transaction so ordering is decided authoritatively, with clients reconciling to the committed result.

Challenge

Broadcasting every bid to every connected client saturated the socket layer at peak.

Solution

Scoped subscriptions per listing so clients only receive updates for what they are watching.

The impact

What became easier, better or more effective.

Bidnest went live for a semester rush and held. A thousand students can bid on the same listing at once and all of them see the same price within a fifth of a second. Parents can bid and message on a student’s behalf for the first time, and landlords let the market find the price instead of guessing it.

“We had a hard launch date tied to the semester. They planned around it from day one, cut scope honestly instead of quietly, and shipped on the day. Launch week was boring, which was the point.”

Co-founder · Student housing marketplace

1,000+

concurrent bidders without a conflict

Bid acceptance is serialised on the server, so there is one authoritative order and no listing is ever awarded twice.

200 ms

from a bid to every screen updating

Students, parents and landlords are looking at the same number at the same moment, which is what makes an open auction fair.

dashboards, one per role

Students, parents and landlords each get the actions and information that matter to them, and nothing else.

Stack