Worked on the grafana/cog repository to deliver covariant TypeVar support within the Builder Template, focusing on enhancing type relationships and safety for generic builder implementations. Leveraging Python and applying principles of generic programming and type hinting, the developer adjusted the builder’s contained type to align with covariant expectations, thereby reducing the risk of type mismatch errors. This update stabilized downstream usage and facilitated safer refactoring of builder-related code. The work improved maintainability and future extensibility by clarifying generic usage, ultimately reducing brittle type relationships and supporting more robust client code without introducing new bugs during the development period.