The client is a top-tier regional financial institution serving over 15 million customers across multiple continents. Their primary services include retail banking, corporate wealth management, and international remittances. Over the past decade their customer base grew exponentially, leading to a massive increase in daily transaction volumes. Their legacy infrastructure, built primarily on monolithic architectures and on-premise servers, began showing signs of severe strain and struggled to maintain the agility the modern digital banking landscape requires.
The legacy codebase was difficult to maintain, which made integrating new payment methods such as digital wallets and cryptocurrencies incredibly slow and risky. Compliance with evolving PCI-DSS standards was becoming increasingly complex and costly, because a single change in a monolithic application required full-system regression testing.
Data consistency across distributed databases was another major hurdle: the legacy system relied on eventual consistency models that sometimes produced temporary financial discrepancies.