Marco Mazzei focused on backend reliability for the mamazzei-edu/pi-2024-multiplataforma repository, addressing a critical server startup issue. He resolved a merge conflict in server.js by removing a duplicate Express app initialization and correcting the imports for cors, dotenv, and mongoose, ensuring consistent server boot across environments. Working primarily with JavaScript, Node.js, and Express.js, Marco’s debugging and code hygiene efforts eliminated startup failures and reduced deployment friction. While the work centered on a single bug fix rather than new features, it demonstrated careful attention to stability and maintainability, resulting in a smoother development workflow and more reliable application deployments.