ReadingGarden Kotlin Migration Backend

Overview

Legacy-compatible migration project that replaced the Django backend of an existing Flutter reading log app with Kotlin/Spring Boot

Highlights

1. Legacy Migration

   Reimplemented Django-based APIs in Kotlin/Spring Boot while preserving the existing app contract

2. Troubleshooting

   Django snake_case response envelopes broke app compatibility after the Kotlin rewrite — pinned legacy response snapshots as contract fixtures and auto-compared them in CI so response contracts stayed intact through the migration

3. Domain Modularization

   Split package structure into auth, book, garden, memo, push, scheduler, and app domains

4. API Compatibility

   Verified compatibility for legacy response envelopes, snake_case fields, JWT authentication flow, and image upload/retrieval paths

5. DB Migration

   Managed schema changes with PostgreSQL + Flyway and secured production schema stability with Hibernate validate

6. Deployment Automation

   Built OCI A1 deployment with GitHub Actions and Docker images, including blue-green deployment through Caddy upstream switching

7. Operational Observability

   Configured Actuator/Prometheus metrics, Grafana dashboards, Loki log collection, and health/docs/smoke check based operations

8. Test Strategy

   Verified the full Controller-Service-Repository flow with Testcontainers PostgreSQL integration tests and legacy contract fixtures