Worked on the facebook/buck2-prelude repository to enhance crash debugging for merged libraries by introducing targeted instrumentation within the merge-map debugging path. Focused on build system development and debugging tools, the work involved reporting non-asset constituents in merged library groups, which enables faster triage and resolution of crashes when libraries transition to non-asset status. Using Starlark, the changes improved the reliability and maintainability of the build process by increasing observability and supporting proactive issue detection. This approach reduced mean time to resolution for crash investigations, contributing to greater product stability and efficiency for developers working with complex build systems.