Worked on the gui-cs/Terminal.Gui repository, focusing on refining the ListView component’s selection behavior to match documented expectations. Addressed a key bug by updating the default value of AllowsMultipleSelection, ensuring that single and multiple selection modes now behave predictably for end users. This change was supported by expanded unit test coverage, which improved regression safety and maintainability. The approach emphasized test-driven development and close alignment with product documentation, reducing potential user confusion and support issues. Utilized C# and .NET for GUI development and software design, demonstrating a methodical approach to quality assurance and collaborative open-source contribution.