Spring Boot Interview FAQs

Dependency Injection (DI) is an Inversion of Control pattern where the Spring container creates and wires object dependencies instead of the class constructing them. Prefer constructor injection for testability. Interviewers expect you to contrast field vs constructor injection and explain bean scopes.

@Service
@RequiredArgsConstructor
public class OrderService {
  private final PaymentClient payments;
}

Interview tip: Prefer constructor injection over field injection.

• Using field injection everywhere
• Confusing DI with service locator