Java Spring Boot Backend Development

What Problem It Solves

When building Java backends, the hard part is rarely a single endpoint. It is the engineering discipline around Spring Boot projects: business logic leaking into controllers, entities exposed directly, transactions that do not roll back, N+1 queries, timezone bugs, and bloated Docker images. These details make services harder to review, test, and operate in production.

How the Skill Works

The skill is focused on Java Spring Boot backend development. It prefers Maven, Java 17 LTS, and common Spring Boot starters. It organizes work around a layered architecture: Controller handles HTTP binding, validation, and response wrapping; Service contains stateless business logic; Mapper or Repository handles data access only, with DTOs and MapStruct separating entities from APIs. The materials cover REST conventions, unified responses, @RestControllerAdvice for global errors, SLF4J logging levels, application.yml multi-profile setup, and testing with JUnit 5, Mockito, and TestContainers. It also addresses common stacks such as MySQL, PostgreSQL, JPA, MyBatis-Plus, Spring Security, Spring Cloud, and Docker or Kubernetes deployment. For debugging or specific patterns, it points to references/spring-boot-common-patterns.md and references/troubleshooting.md.

Boundaries and Caveats

It is useful for creating or refactoring Spring Boot services, reviewing Java code, and troubleshooting startup failures or dependency conflicts. It is less relevant for pure frontend work or non-Spring stacks. If a project requires Gradle, legacy Java versions, or custom frameworks, follow those constraints first. Production decisions still need real access control, audit logs, monitoring, and capacity planning.