Payment Gateway Platform
A scalable payment processing system handling millions of transactions with real-time fraud detection.
Legacy payment systems couldn't handle peak load during flash sales, causing revenue loss and poor user experience. The monolith architecture meant any single point of failure brought the entire system down.
Designed a distributed payment pipeline with async processing queues and real-time fraud scoring. Each stage of the pipeline is independently scalable and fault-tolerant.
Event-driven microservices architecture.
Kafka handles transaction events between services.
Redis caches session data and rate limits.
PostgreSQL stores finalized transactions with read replicas for reporting queries.
Docker Compose for local dev, Kubernetes in production.
The system processes 3x the previous peak throughput with zero downtime during flash sales. Fraud detection latency dropped from 200ms to 15ms per transaction. Infrastructure costs reduced by 40% through auto-scaling.