Most marketplaces are two-sided: buyers and sellers. Stripe powers the money, the platform takes a cut, everyone's happy.

A three-sided marketplace is a different beast. We needed sellers to list products, creators to promote them, and buyers to purchase — with money, attribution, and incentives flowing correctly between all three on every single transaction.

This is how we built Peddlum, the architecture decisions we made, and the things that almost broke us.

The Core Problem

In a two-sided marketplace, a sale is simple: buyer pays seller, platform skims a fee, done.

In our model, a single sale has to:

Charge the buyer via Stripe

Split revenue between platform, seller, and creator

Attribute the sale to the right creator's tracking link

Apply the creator's tier multiplier

Update three different wallets atomically

Trigger fulfillment (file delivery OR SaaS webhook)

Fire notifications to all three parties

Get any step wrong and someone is underpaid.…