Rebuilding a Tier-1 Bank on Cloud-Native Rails
Migrated a 40-year-old COBOL core banking system to a cloud-native microservices architecture — without a single minute of customer downtime.
NexaBank was losing $18M/year in maintenance costs on legacy mainframes, unable to ship new products faster than one release per quarter, and facing regulatory pressure to modernize. A previous vendor had failed to migrate after 3 years and $40M.
Our architects designed a phased strangler-fig migration: 47 event-driven microservices in Go, a Kafka-based ledger backbone, and a real-time fraud-detection model deployed on Kubernetes with an SRE-grade observability layer.
Full core banking replatform delivered in 18 months with zero customer-facing downtime. Release cadence went from quarterly to daily, fraud losses dropped 61%, and infrastructure costs fell 73%.