Worked on enhancing environment variable handling in the prisma/prisma repository by introducing improved type safety and developer experience. Developed a new EnvKey type and updated the env helper to support interface-based environment variable types, allowing for more flexible and robust type constraints. Focused on maintaining backward compatibility and ensuring no changes to runtime behavior, while aligning updates with existing documentation. Added comprehensive type-level tests to verify compatibility with both interfaces and type aliases. Utilized TypeScript and testing methodologies to deliver these improvements, emphasizing type safety and maintainability in the codebase. No bugs were reported or fixed during this period.