How Stripe Uses Idempotency Keys to Prevent Double Charges

In this episode, Lucas and Luna dive into one of the most elegant patterns in distributed systems: the idempotency key. Using Stripe's payment API as the central case, they explain how a single HTTP header prevents duplicate charges during network retries, how Shopify applies the same pattern to order creation, and why idempotency is a fundamental principle for any system that deals with money, inventory, or state changes. The discussion covers the mechanics of idempotency keys, their role in exactly-once semantics, and practical trade-offs like key expiration and storage. Listeners will walk away understanding a concrete tool to make their own APIs safer. #Idempotency #Stripe #PaymentAPI #DistributedSystems #APIDesign #ExactlyOnce #HTTP #Shopify #RetryLogic #SystemsDesign #FaultTolerance #Engineering #Backend #TechnicalLeadership #FexingoBusiness #BusinessPodcast #CTOPodcast #Architecture Keep every episode free: buymeacoffee.com/fexingo