advanced · webhooks

Design Webhook Delivery

Design webhook delivery for a payments platform. What must the contract cover for consumers to build something reliable?

Practical scenario

Partners integrate “payment succeeded” webhooks to release goods, and one partner's flaky endpoint causes retries that their handler processes as two separate payments.

What it tests

  • • At-least-once delivery and its consequences
  • • Retry schedule, ordering, and dead-lettering
  • • The security contract: signatures, timestamps, replay