This tutorial outlines the process of modernizing a simple C++ application to Java, utilizing GitLab Duo's AI capabilities to aid in the refactoring. It explains how to run and understand the original C++ application and provides a step-by-step guide on how to migrate it to a memory-safe Java application, ultimately demonstrating that the refactored application functions as intended. Additionally, it promotes the use of GitLab Duo for effective modernization tasks.