How API Webhook Retries Cause Duplicate Payments

Episode 54 of The Developer Tools Podcast explores how webhook retries in payment APIs can trigger duplicate charges — and why standard at-least-once delivery guarantees are often the culprit. Lucas and Luna break down a real-world case from a mid-size e-commerce platform that lost $40,000 in two hours due to missing idempotency checks on webhook receivers. They discuss how idempotency keys, exactly-once semantics, and receiver-side deduplication can prevent these failures. Listeners will learn the difference between webhook retries and API idempotency, how Stripe and PayPal handle delivery guarantees, and why your payment integration needs a dedup table before it goes to production. #WebhookRetries #DuplicatePayments #PaymentAPIs #IdempotencyKeys #ExactlyOnceDelivery #Deduplication #StripeAPI #PayPalAPI #Ecommerce #DeveloperExperience #APIReliability #Business #Technology #FexingoBusiness #BusinessPodcast #DeveloperTools #Infrastructure #SoftwareEngineering Keep every episode free: buymeacoffee.com/fexingo