Sami worked on improving the Docker build workflow for the METR/vivaria repository, focusing on stabilizing CI/CD processes. By addressing an issue where builds ran with an undefined builder name, Sami refactored the ensureBuilderExists function to reliably create and return the correct builder, enhancing build reliability. The solution included adding unit tests to validate builder existence and creation logic, which helps prevent future regressions. Sami’s work, using JavaScript, TypeScript, and Docker, reduced flaky CI outcomes and accelerated developer iteration. The depth of the changes reflects a strong understanding of CI/CD pipelines and a methodical approach to workflow reliability and testing.