Andy focused on stabilizing the renderer for the thinking-machines-lab/tinker-cookbook repository, addressing a regression that caused crashes when user messages were absent. Using Python and backend development skills, Andy implemented a targeted fix to ensure the renderer handled empty input gracefully, preventing runtime failures and improving user experience. The solution included adding regression tests to validate correct token weight assignment and to guard against similar issues in the future. This work enhanced the maintainability and reliability of the codebase, demonstrating careful attention to edge-case handling and test coverage, and laying a solid foundation for future improvements in renderer resilience.