How We Improved Payment System Throughput by 25% Using Apache Kafka at a Fortune 500 FinTech

How We Improved Payment System Throughput by 25% Using Apache Kafka at a Fortune 500 FinTech By Disha Sune — Java Backend Engineer | Spring Boot | Kafka | AWS | Fiserv The Problem At Fiserv, our payment processing platform handled millions of financial transactions daily for 600+ enterprise clients including McDonald's, Google, and Domino's. As transaction volumes grew, our legacy synchronous REST API architecture started showing cracks: API response times were spiking during peak load periods D