Kosta Tovstik enhanced type safety for the PostgreSQL client integration in the grafana/k6-DefinitelyTyped repository by refining the Client.connect method’s return type. Using TypeScript and Node.js, Kosta updated the API to return a Promise of ClientBase and Client, aligning with stronger type guarantees and improving usability for downstream projects. The work included updating tests to ensure compatibility with the new API surface, supporting safer TypeScript usage and reducing potential runtime errors. This focused feature addressed a core aspect of database management, demonstrating a thoughtful approach to type correctness and developer experience within a widely used TypeScript codebase.