Worked on the cube-js/cube repository to enhance the reliability and correctness of the Playground SQL workflow by addressing a bug in the Generated SQL tab. Focused on correcting SQLQuery types and improving data handling within client-core, the work involved implementing targeted unit tests to validate the flow of SQL query data. This approach reduced edge-case errors in the user interface’s SQL generation and strengthened the overall developer experience in the playground. The solution demonstrated effective use of TypeScript and unit testing, with an emphasis on test-driven development practices to ensure robust integration and maintainability of the SQL generation feature.