During February 2025, TJ Harvey focused on security hardening for the llvm/torch-mlir repository, addressing a critical vulnerability in YAML handling. He replaced insecure YAML loading with a safe loader in Python, mitigating the risk of arbitrary code execution from untrusted YAML inputs. This backend development work involved updating both the codebase and documentation to reflect secure-by-default practices, ensuring that YAML parsing aligns with industry standards for reliability. Although no new user-facing features were introduced, the targeted bug fix reduced the attack surface and improved production security, demonstrating depth in Python programming and careful attention to secure YAML processing.