Testing Spring Boot applications with YugabyteDB using Testcontainers allows developers to write integration tests that mimic the production environment, providing a more realistic testing scenario. This approach uses Testcontainers, a Java library that provides lightweight, throwaway instances of common services running in a Docker container, to create a real database for testing purposes. By defining the library dependency and initializing the container programmatically or via the configuration file, developers can integrate Testcontainers into their Spring Boot applications and write integration tests that focus on the service layer and repository components. The process involves setting up prerequisites such as JDK 17 or above and Docker Engine, and then using annotations like `@SpringBootTest`, `@AutoConfigureTestDatabase`, `@Testcontainers`, and `@ActiveProfiles` to configure the application to use the real database through Testcontainers.