Payment Bank - High-Throughput Transaction System

Architected and developed a high-performance payment processing system for a banking application. Implemented reactive programming patterns using Akka Streams to handle concurrent transactions efficiently. Integrated with multiple payment gateways and banking APIs.

JavaAkka StreamsSpring BootPostgreSQLRedisDockerKubernetesKafka

Key Achievements

4.3x increase in TPS (700 → 3000)
99.99% uptime achieved
Zero payment processing errors during peak hours
Successfully handled 10M+ transactions monthly

Challenges

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System could only handle 700 transactions per second
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Blocking I/O operations causing thread pool exhaustion
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Transaction failures during peak load periods
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Complex state management for payment workflows
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Need for exactly-once payment processing guarantees
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Integration with multiple payment gateways with varying response times

Solutions

Implemented reactive programming using Akka Streams for non-blocking I/O
Designed backpressure handling to manage load effectively
Implemented distributed transaction management with saga pattern
Added comprehensive error handling and retry mechanisms
Increased TPS from 700 to 3000 (4.3x improvement)
Achieved 99.99% uptime with robust failure recovery
Implemented real-time monitoring and alerting with Grafana

Technologies & Tools

Java

Akka Streams

Spring Boot

PostgreSQL

Redis

Docker

Kubernetes

Kafka