In February 2026, Ulf delivered a base-image fingerprinting feature for Docker images in the php/frankenphp repository, focusing on reproducible builds and enhanced image integrity. He implemented a mechanism that derives fingerprints from bake metadata and stores them under a vendor label, improving traceability and governance of deployed images. Ulf also developed a local testing script in bash to reproduce fingerprint generation and compare results, ensuring reliability and consistency in image builds. His work leveraged CI/CD, DevOps practices, and scripting in bash, hcl, and yaml, providing a reusable approach that supports audit trails and strengthens image management across deployments.