During May 2025, Sakamoto enhanced the google/perfetto repository by implementing a new feature for the Linux Perf plugin that displays callstack source file, line number, and mapping information. This work involved updating SQL queries to retrieve additional fields required for accurate source and location mapping, as well as refining UI metric definitions to visualize the new callstack data. Sakamoto integrated these changes across the backend and frontend, ensuring seamless data flow and minimal impact on user experience. The project leveraged skills in SQL, TypeScript, and performance analysis, resulting in a cohesive end-to-end solution prepared for QA review without introducing regressions.