Ad Marketplace
A two-sided marketplace for physical ad space.
Problem
Buyers who want physical ad space and owners of that space had no direct way to transact — matching, pricing, and payment were three separate manual problems being solved by email and spreadsheets.
Role
Designed and built the marketplace end-to-end: the matching and bidding mechanics, the transaction layer, and the payout pipeline connecting both sides of the deal.
Stack
Architecture
Marketplace state and payment state are kept as one source of truth — a bid or listing change and its financial consequence commit together, not as two systems reconciled after the fact.
- Step 1
Listing & bidding
Ad space owners list inventory; buyers place bids against real-time availability.
- Step 2
Match engine
Server-side logic resolves bids against listings and locks the transaction state.
- Step 3
Stripe settlement
Payment capture and marketplace payout run against the same matched transaction.
- Step 4
Live activity feed
Bid and match activity streams to both sides via Supabase realtime.
Outcome
A working two-sided marketplace where listing, bidding, and payout are one continuous flow instead of three disconnected manual steps — the kind of system that only has to be built once if the plumbing between payments and marketplace state is done right.