Healthcare Provider Portal: JSF to React Migration

A healthcare SaaS provider was running a patient portal built with JSF 2.2 and PrimeFaces. The frontend was slow, mobile-unfriendly, and increasingly difficult to maintain. Competing products had modern, responsive interfaces while theirs felt stuck in 2010. The portal served 500,000+ patients and healthcare providers. The UI was deeply coupled with backend EJB services through managed beans, making frontend changes risky and time-consuming. Key challenges: - Must maintain HIPAA compliance throughout migration - Cannot disrupt active patient sessions or appointments - Development team has no React experience - Need to support mobile devices (60% of traffic) - Cannot afford a "big bang" rewrite

Implemented an incremental frontend modernization strategy: **Phase 1: Architecture Planning (Month 1)** - Created REST API layer to decouple frontend from EJBs - Designed component-based UI architecture in React - Established design system using Material-UI - Set up micro-frontend architecture for gradual rollout **Phase 2: API Layer & Pilot Screen (Months 2-3)** - Built Spring Boot REST API wrapper around existing EJBs - Migrated login/authentication screen to React - Implemented responsive design for mobile - A/B tested with 10% of users **Phase 3: Core Functionality Migration (Months 4-8)** - Migrated appointment scheduling (most-used feature) - Rebuilt patient dashboard with real-time updates - Implemented medication management interface - Migrated provider messaging system - Progressive rollout to 100% of users **Phase 4: Complete Transition (Months 9-10)** - Migrated remaining admin screens - Removed JSF dependencies - Optimized bundle size and performance - Comprehensive accessibility audit (WCAG 2.1 AA)