François Joulaud worked on stabilizing the image pipeline for the radiofrance/dib repository, focusing on improving rebuild reliability and maintainability. He addressed a bug in the dependency management logic by decoupling image rebuild propagation from parent status, ensuring that all dependent images are rebuilt as needed. Using Go, he refactored the DAG package, removing an unused and buggy Filter function to reduce complexity and technical debt. His work emphasized code cleanup and clear commit history, resulting in a more robust and maintainable build system. The depth of his changes improved pipeline correctness and reduced fragility in the image rebuild process.