During November 2024, Ilias Polyzos refactored the CopyDir functionality in the pulumi/opentofu repository to enhance the reliability and modularity of directory copy operations. Focusing on Go development, he improved error handling by introducing descriptive messages using fmt.Errorf for file operations and symlink evaluation. He also extracted the file copying logic into a dedicated copyFile function, which increased code readability and modularity. This targeted change addressed maintainability concerns and laid the foundation for more robust file copy workflows, reducing operational risk and supporting faster future iterations. His work demonstrated depth in error handling, file operations, and thoughtful refactoring.