Worked on the Turso repository to address SQL collation correctness, focusing on the handling of the BETWEEN clause in WHERE expressions. Applied Rust and SQL expertise to fix an issue where the left-hand side collation was not respected, ensuring queries now follow proper collation rules. Developed targeted reproduction tests and updated test snapshots to verify the fix and maintain alignment with expected behavior. Emphasized robust database testing and regression safety throughout the process, preserving performance characteristics and test suite stability. The work improved SQL correctness across collations, demonstrating careful attention to detail in database management and test-driven development practices.