Alex Nieto focused on backend and game server development for the PaperMC/Paper repository, addressing a nuanced bug related to Ender Pearl ownership semantics. Working in Java, Alex implemented a targeted fix that ensures Ender Pearl ownership is either retained or reset on player disconnect, depending on legacy configuration settings. This approach preserved backward compatibility for older server setups and reduced discrepancies in item ownership behavior. By refining the disconnect-path logic with minimal code changes and clear configuration semantics, Alex improved the reliability of legacy item handling. The work demonstrated strong debugging and code review skills, emphasizing maintainability and compatibility in Java environments.