Measuring a Payment Gateway: North Star, Approval Funnel and Risk Guardrails

You are the product manager for a payment gateway: the service a business connects to its checkout so that its customers can pay online, and that sends each payment on for approval and settlement. Which metrics would you use to judge whether the product is succeeding? Choose the metric you would treat as the main measure of success, explain why, and describe the metrics you would track around it. ```hint Two customers, one payment Ask who has to be satisfied for the gateway to grow, then follow a single payment from the moment the shopper presses pay until the money reaches the business. Every point where that payment can stall, fail or go wrong is a candidate for measurement. ``` ### Clarifying Questions - Is this a third-party gateway selling to many merchants, or the payment step inside one company's own marketplace or app? - Is the product newly launched and still signing up merchants, or established and competing to keep and grow volume? - Which payment methods and regions are in scope: cards only, or also bank transfers and digital wallets, in one country or several? - How does the gateway earn money: a percentage of each payment, a fixed fee per transaction, a subscription, or a mix? ### What a Strong Answer Covers - A short explanation of how the gateway creates value for merchants and for the people paying, and a stated goal. - One north-star metric, justified against the alternatives it beats. - Supporting metrics across the merchant lifecycle and the life of a single payment, including approval, failure and speed. - Guardrails on fraud, disputes, wrongly declined payments and reliability that stop the north star from being gamed. - How the metrics are broken down and acted on, for example by payment method, issuing bank, region and merchant. ### Follow-up Questions - The approval rate fell sharply overnight. How would you find the cause? - Stricter fraud rules cut losses but decline more genuine payments. How do you decide where to set them? - A large merchant splits its payments between your gateway and a competitor's. Which metric tells you whether you are winning its volume, and how would you move it?