Tech Stack
Technology Layers
Version Table
| Concern | Choice | Version |
|---|---|---|
| Language | Kotlin | 1.9.22 |
| Runtime | JDK | 21 |
| Framework | Spring Boot | 3.2.3 |
| Build | Gradle (Kotlin DSL) | 8.6 |
| Streaming | Kotlin Coroutines / Flow | 1.7.3 |
| Messaging | Spring Kafka | (managed by Boot BOM) |
| Database | PostgreSQL + Flyway | (managed by Boot BOM) |
| API Docs | SpringDoc OpenAPI | 2.3.0 |
| Auth | JJWT | 0.12.3 |
| Testing | Kotest | 5.8.1 |
| Mocking | MockK | 1.13.9 |
| Logging | kotlin-logging (mu) | 3.0.5 |
Dependency Version Policy
Common Pitfall
Never add flyway-database-postgresql as a dependency. It does not exist in Flyway 9.x (managed by Boot 3.2.3 BOM). flyway-core is sufficient.