Java

Singleton, prototype, request/session and other Spring bean scopes, including lifecycle and thread-safety implications.

Pointcuts, advice, proxies, aspect ordering, and the self-invocation limitation of proxy-based Spring AOP.

Dependency injection through components/configuration with constructor injection, explicit dependencies, and container-managed lifecycle.

Dependency resolution by type/qualifier/name metadata and the BeanPostProcessor infrastructure behind annotation injection.

Proxy/interceptor transaction flow from metadata lookup to transaction manager begin/commit/rollback.

Packaging reusable dependencies plus conditional auto-configuration and typed configuration properties without surprising applications.

Spring cache abstraction usage, cache annotations, cache keys, invalidation, and the limits of local or remote cache providers.

Executable Boot archive layout, launcher/class-loader concept, nested dependencies, and why exact launcher classes are version-specific.

Conditional creation of SqlSessionFactory, mapper integration, transaction participation, and application override points.

How Boot conditionally configures MVC defaults while allowing application customization and full override.