Avi Bartavi enhanced the robustness of certificate authority tag parsing in the letsencrypt/boulder repository by updating the backend to recognize the 'issuevmc' and 'issuemail' tags in CAA records. Working primarily in Go and focusing on backend development for certificate authority systems, Avi implemented a recognition-only path for the 'issuevmc' tag to ensure backward compatibility and minimize operational risk. This targeted fix addressed a specific bug that previously caused failures when encountering diverse CAA records, thereby improving system stability and compatibility. The work demonstrated careful risk management and contributed to more reliable certificate issuance flows for dependent services.