How I write production-ready Spring Boot applications

A detailed walkthrough of how an experienced Java developer structures production Spring Boot applications using Domain-Driven Design principles. Covers aggregate root-based package organization, a three-layer structure (repository, usecase, web) per aggregate, value objects, a custom repository interface pattern that hides Spring Data JPA, use-case classes instead of monolithic services, and a clean web layer with separate Request/Response DTOs. Also explains why this approach is preferred over Hexagonal Architecture for most Spring Boot projects.