Modernizing Legacy Banking Core Systems for Regional Bank

A mid-sized regional bank with 2.3 million customers and 450 branches across 12 states was struggling with a 20-year-old core banking system. The legacy platform couldn't handle the growing transaction volume, lacked modern API capabilities, and required expensive maintenance. Edvirra was brought in to design and implement a complete core banking modernization.

Core Banking System Modernization

The project began in Q2 2022 with a comprehensive assessment of the existing system. We identified over 200 integration points, 15 legacy databases, and multiple batch processing systems that needed to be migrated. Our team designed a cloud-native architecture using microservices, containerized the applications with Docker, and deployed on AWS EKS.

The migration was executed in phases over 18 months. We started with non-critical systems like customer onboarding, then moved to transaction processing, and finally migrated the core account management system. Each phase included extensive testing, rollback plans, and parallel running with the legacy system for 3 months before cutover.

Key technical decisions included using PostgreSQL for transactional data, Redis for caching, Kafka for event streaming, and implementing a GraphQL API layer for frontend applications. We also integrated real-time fraud detection using machine learning models that analyze transaction patterns.

The new system went live in Q4 2023. Since then, the bank has seen significant improvements: