Node.js & PostgreSQL Backend Engineer for Webhook Relay System

ZestPay Africa is building a mission-critical webhook dispatch system capable of processing up to 50,000 inbound events per minute.

Scope:
- Build a resilient event queue worker using Node.js / TypeScript and BullMQ (Redis).
- Implement exponential backoff, dead-letter queue, and automated replay capabilities.
- Write idempotent webhook signatures (HMAC SHA-256) and payload delivery tracking.
- Deliver clean documentation and automated test suites.