Spring Boot Pre-Interview Guide Part 7: Advanced Patterns — Spring Boot 4 · Kotlin 2.3 · Events · Async · Multi-module
On Spring Boot 4 with Kotlin 2.3, the patterns that make your assignment stand out. Domain-and-side-effect separation via @TransactionalEventListener, async fan-out with @Async + CompletableFuture, file upload validation, URI versioning, layered vs Hexagonal vs CQRS, and multi-module Option A (DIP) vs Option B (pragmatic) — written without Lombok, using Kotlin primary constructors and val/var.