Arpan Pandey developed robust history persistence and user-facing history features for the codecrafters-io/shell-tester and build-your-own-shell repositories, focusing on reliable command storage and retrieval across sessions. He stabilized CI/CD pipelines by splitting build stages and refining test infrastructure, which improved feedback speed and reduced flakiness. On codecrafters-io/frontend, Arpan refactored animation components using JavaScript and Tailwind CSS, enhanced test reliability, and optimized matching strategies for better performance. His work involved backend and frontend development, Docker-based build automation, and comprehensive acceptance testing. The depth of his contributions is reflected in improved determinism, maintainability, and user experience across multiple codebases.