During May 2025, Jakub Tomasiak modernized the rootfs build pipeline for the kata-containers/kata-containers repository, focusing on reliability and configurability for Ubuntu 24.04 and multi-architecture environments. He migrated the rootfs builder from multistrap to mmdebstrap, aligning with upstream changes and improving build reproducibility. Jakub also updated runtime configurations to support stricter systemd sandboxing, ensuring compatibility with hardened environments. By exposing REPO_URL and REPO_COMPONENTS variables in osbuilder scripts, he enabled flexible repository and package component selection. His work leveraged Shell scripting, Linux packaging, and system administration skills, delivering deeper cross-architecture support and more customizable deployment pipelines for users.