Case Study: Scaling Fraud Defenses for a Marketplace on Stripe

The Challenge

A high-growth marketplace in the collectibles space came to us as they were moving into Stripe’s bigger volume tiers. Fraudsters had noticed their growth too—stolen cards, chargebacks, and coordinated fraudulent abuse were becoming a daily drag. They were already on Stripe’s transaction fraud solution known as Radar. But here’s the reality: Radar will show you plenty of interesting fraud signals inside Stripe’s dashboard, yet those same signals aren’t available when you go to actually block fraud with rules. That gap leaves merchants exposed at scale.

What We Did

We worked side by side with their team to close those gaps:

• Smarter Radar Rules tuned to their actual customer patterns.
• Honeypots on social platforms to surface how fraudsters were coordinating.
• Velocity and entity-reuse checks to stop repeat bad behavior in real time.
• Cleaner analyst signals so fraud stood out instead of drowning in noise.

The Impact

Within two weeks:

• Fraudulent abuse on the platform dropped.
• Good customers stopped getting caught in blunt rules.
• Fraudster playbooks were spotted before they ever succeeded at checkout.

The Radar Gaps

Stripe Radar is great for getting started, but merchants at scale quickly run into three issues:

• Unusable Signals: Risk Insights surfaces data points you wish you could act on, but those attributes aren’t exposed as rule attributes when it comes to actually building the rules.
• Blunt Controls: Out-of-the-box rules are designed for the average merchant, not your business model, which means more false positives as you grow.
• Fraudster Adaptation: The same playbooks get recycled across merchants. Without deeper defenses, fraudsters learn exactly how far Radar rules can be pushed.
These gaps don’t show up in Stripe’s sales pitch—but they show up in your chargeback ratio.

Why This Matters

For obvious reasons, we cannot name our user publicly, because you know, fraudsters read too. But the story is always the same: once you cross into mid-to-enterprise scale on Stripe, Radar’s default setup starts leaving cracks that fraudsters know how to exploit.

That’s why we’re building Canonical: the next generation of transaction fraud tooling for serious Stripe merchants. Our goal is simple. Take the signals you already wish you could act on, make them actionable in real time, and give you the controls to intercept fraudulent payments at checkout without putting good customers through friction.