Testing Webhooks: The Pattern I Keep Reaching For

Webhook testing has long relied on ngrok tunnels, arbitrary sleep calls, and manual steps — but there's a cleaner approach. The 'inbox pattern' separates HTTP reception from business logic processing, making each layer independently testable. Combined with signature verification tests, injectable retry scheduling, and deliberate out-of-order delivery scenarios, you get a fully deterministic test suite that runs in CI without external dependencies.