Checkout Flows
That Don't Break.
Use Gestalt when checkout bugs are costing you money. Map the payment flow as a system with states, retries, and data—not just screens.
Product Managers
Owning conversion and preventing revenue leaks.
Engineering
Shipping complex payment logic with confidence.
QA Leads
Tired of playing "edge case roulette" every release.
How it works
Frontstage: States
Map visual states: Cart ? Shipping ? Payment ? Confirmation. Include the ugly parts: 3DS challenges, declines, and timeouts.
Backstage: Logic
Model the provider interactions. Webhooks, reconciliation jobs, and retries live here, visible but separate.
Data Objects
Define the entities (Orders, Invoices, Events) flowing through the wires to inform your schema.
The Output
Edge Case Map
Document failures so they don't surprise you in prod.
Schema Export
Export SQL definitions for your payment tables.
The Contract
Alignment between Frontend and Backend without meetings.