E-commerce Platform: Legacy Spring to Spring Boot Cloud-Native

A national retail chain operated an e-commerce platform built on legacy Spring Framework 3.2 with XML configuration. The monolithic application was deployed to on-premise servers, making scaling during peak seasons (Black Friday, holidays) extremely expensive and slow. The platform handled $500M in annual online revenue but couldn't scale quickly enough during traffic spikes. Infrastructure costs were high, deployment velocity was slow (monthly releases), and the development team struggled with the aging codebase. Critical requirements: - Must handle 100x traffic spikes during sales events - Need to reduce infrastructure costs - Cannot risk revenue loss during migration - Must enable continuous deployment - Need to modernize without rewriting business logic

Executed a cloud-native modernization strategy: **Phase 1: Containerization & Cloud Prep (Months 1-2)** - Containerized existing application with Docker - Deployed to Kubernetes staging environment - Implemented health checks and monitoring - Set up CI/CD pipeline **Phase 2: Spring Boot Migration (Months 3-5)** - Migrated to Spring Boot 3 with minimal code changes - Converted XML configuration to Java config - Implemented Spring Boot Actuator for monitoring - Migrated to embedded Tomcat - Deployed to production with feature flags **Phase 3: Microservices Decomposition (Months 6-9)** - Extracted cart service as first microservice - Migrated product catalog to separate service - Implemented API Gateway pattern - Set up distributed tracing with OpenTelemetry - Migrated order processing service **Phase 4: Cloud-Native Optimization (Months 10-12)** - Implemented auto-scaling based on metrics - Added Redis for session management - Integrated with AWS managed services - Set up blue-green deployments - Implemented comprehensive monitoring dashboard