Himanshu Mahajan refactored the AST import logic for struct types in the lfortran/lfortran repository, focusing on maintainability and code clarity. He introduced a dedicated utility function in C++ to streamline the import process within the AST common visitor, which improved readability and reduced the risk of edge-case failures. By simplifying the struct type import logic, Himanshu addressed potential sources of regressions and lowered the ongoing maintenance burden for the codebase. His work demonstrated a thoughtful approach to code refactoring and software development, emphasizing robust engineering practices and contributing to the long-term stability of the lfortran project.