Payment Systems 6 min read
Bulletproof Razorpay Webhooks
Building idempotent payment webhook handlers that survive network retries, race conditions, and duplicate delivery with MongoDB change streams.
The Problem with Webhooks
Razorpay, like all payment providers, guarantees 'at-least-once' delivery for webhooks. This means the same payment.captured event can arrive multiple times. Without proper handling, this leads to duplicate order fulfillment — a critical business bug.
Idempotency via MongoDB
The solution was to use the Razorpay payment ID as an idempotency key. Before processing any webhook, the handler checks MongoDB for an existing order with that payment ID.
Implementation
Verified Outcomes
Zero duplicate orders in production across 1,500+ webhook events
All webhook events processed within 500ms average
Webhook handler handles bursts of 50 concurrent retries gracefully