Kartar Singh contributed to both the google/perfetto and puppeteer/puppeteer repositories, focusing on build stability and testing enhancements. In google/perfetto, Kartar addressed CI reliability by correcting the header include order between Psapi.h and Windows.h, using C++ and build system expertise to resolve Chromium bot build failures and prevent future regressions by disabling clang-format for the affected code block. Later, in puppeteer/puppeteer, Kartar developed enhanced touchscreen testing by implementing detailed pointer event handling in TypeScript and HTML, improving the robustness and accuracy of automated tests. The work demonstrated careful attention to code hygiene and targeted, high-impact engineering solutions.