Worked on the datametica/calcite repository to enhance SQL query processing by implementing selective expression simplification control for computed columns. Developed a skip_simplify directive that allows original expressions to be retained in projections, updating both RexShuttle and RexSimplify to respect this behavior. Addressed a casting issue related to computed columns during table creation, ensuring more reliable query results. Focused on backend development and code refactoring using Java and SQL, with an emphasis on unit testing to validate changes. Improved code style and formatting throughout the codebase, resulting in greater readability and maintainability for ongoing and future development efforts.