Payment System Architecture Simulator
Simulation platform demonstrating resilient payment system architecture.
Screenshots
The Problem
Payment systems must handle retries, duplicate requests, webhook failures, and partial transactions reliably.
The Solution
This simulator models a realistic payment architecture with idempotent APIs and webhook retry logic.
Implementation Details
Handling money requires a different level of engineering rigor. This project is a deep dive into building systems that are eventually consistent but never lose data.
Idempotency Keys
We implemented a global idempotency layer using Redis to prevent double-charging users during network retries. Every request is tracked with a unique key, ensuring that re-submitting a "Pay" request is safe.
Webhook Reliability
Webhooks are notoriously flaky. This simulator includes a dead-letter queue and an exponential backoff retry mechanism to ensure that downstream systems are eventually notified of payment success, even if they are temporarily down.