In January 2026, William F. migrated the Syndica/sig repository’s CircleCI Linux builds to self-hosted runners on AWS EC2, focusing on CI/CD modernization and infrastructure control. He implemented environment adaptations such as non-root execution, sudo for apt commands, and docker_as_user to ensure correct file ownership in kcov jobs. Using YAML and leveraging AWS and Linux expertise, William updated cache management with a -selfhosted suffix to prevent stale caches and coordinated with AWS autoscaling infrastructure for scalable CI. This work improved build efficiency, reliability, and reproducibility, laying a foundation for more predictable and faster CI/CD workflows within the project.