Spring Boot Dependency Injection Overview Provides constructor-first dependency injection patterns for Spring Boot: - mandatory collaborators via constructor injection - optional collaborators via or no-op fallbacks - bean selection via and - validation via minimal context tests before full integration When to Use Use this skill when: - creating a new , , , or class - replacing field injection in legacy Spring code - resolving multiple beans of the same type with qualifiers or primary beans - handling optional features, adapters, or integrations without null-driven wiring - reviewing circular…