Gaurav Purohit developed a code modification evaluation utility for the GoogleCloudPlatform/spanner-migration-tool repository, focusing on backend development and code analysis using Go. He designed the utility to assess the accuracy of line-number identification in code modifications, addressing the need for objective quality measurement. Gaurav implemented comprehensive unit tests in eval_test.go, incorporating metrics such as precision, recall, and F1 to quantify evaluation performance. Additionally, he refactored app_migration_analysis.go to improve field visibility, enhancing API clarity and maintainability. His work demonstrated a methodical approach to testing and maintainability, delivering a robust framework for evaluating and improving code modification processes.