Siaojie Cai worked on maintaining build stability for the facebook/buck2-prelude repository by addressing a dependency compatibility issue. During the month, Siaojie reverted an attempted upgrade of the Commons Compress library from version 1.24.0 to 1.28.0, restoring the previous stable baseline to prevent binary incompatibilities for downstream Buck2 Prelude consumers. This involved updating BUCK build configuration files and validating the change through a targeted revert commit, ensuring minimal disruption to ongoing development. Siaojie’s work focused on build system configuration using BUCK and dependency management, demonstrating careful risk mitigation and attention to compatibility across the project’s build environments.