Monolithic to Microservices Migration for a Leading Retail Bank

Top-5 Canadian Retail Bank

• The bank's Loan Origination and Processing System was a tightly-coupled JEE monolith — a single deployment unit serving every channel, with release cycles measured in months and outages that took down the entire lending business.
• Scaling for peak mortgage demand meant over-provisioning the entire stack, and any change required full regression testing across unrelated modules.

• Kumaran applied domain-driven design to decompose the monolith into bounded contexts — origination, underwriting, document management, decisioning, and disbursement — each becoming an independently deployable Spring Boot service.
• Event-driven communication via Kafka replaced synchronous chains, and a new API gateway preserved backward compatibility for channels during the multi-year migration.
• We stood up a CI/CD pipeline with automated contract tests, canary deployments, and blue-green release patterns to make production changes routine instead of risky.