What is Webhook?
A mechanism where a server sends real-time HTTP POST notifications to a specified URL when specific events occur.
Webhooks are "reverse APIs" — instead of polling for updates, the service pushes data to your endpoint when events happen. For example, Stripe sends a webhook when a payment succeeds, and GitHub sends webhooks on code pushes.
Implementing webhook receivers involves validating signatures (to prevent spoofing), responding quickly (200 status), processing asynchronously, and handling retries for failed deliveries. Webhooks are essential for event-driven integrations.