Over a two-month period, contributed targeted stability and robustness improvements to the mozilla/gecko-dev repository using C++. Focused on bug fixing and code refactoring, first by simplifying sub-document frame existence checks in Document.cpp to eliminate unnecessary warnings, which reduced log noise and improved maintainability for frame-handling code. Subsequently, addressed cache management in the network protocol layer by correcting null callback handling and cache ID extension during invalidation within the Cache Storage Service. These changes enhanced the accuracy and reliability of cache operations, reduced edge-case failures, and supported more efficient debugging and QA processes without introducing new features during this period.