Building Payment Infrastructure at Scale

Payment infrastructure is unforgiving. When money moves, there is no room for approximation. Every architectural decision compounds — a poorly designed webhook system doesn't just cause bugs, it causes financial discrepancies that erode trust.

When we began building Radok Pay, we made a deliberate choice: API-first, always. Every feature visible in the dashboard had to be accessible programmatically. This constraint forced us to design clean service boundaries from day one.

The core challenge was handling the diversity of Nigerian payment methods while maintaining a unified developer experience. Virtual accounts, bank transfers, card payments, and payment links all needed to flow through a single transaction model.

The core challenge was handling the diversity of Nigerian payment methods while maintaining a unified developer experience.

We implemented an event-sourced transaction ledger using MongoDB, with Redis handling idempotency keys and rate limiting. Webhook delivery runs through a dedicated queue service with exponential backoff and dead-letter handling.

The result: a platform that processes over 2 million transactions with 99.9% uptime and consistent sub-200ms API response times. The architecture scales horizontally — adding capacity means adding service instances, not redesigning the system.