Worked on the duckduckgo/apple-browsers repository to improve the accuracy of rule compilation metrics in iOS applications. Addressed a bug where time spent while the app was backgrounded was incorrectly included in rule compilation wait times, potentially skewing performance data. Implemented a solution in Swift by adding an observer for UIApplication.didEnterBackgroundNotification, capturing elapsed time before the app entered the background and excluding it from performance calculations. This approach ensured that only active foreground time contributed to rule compilation metrics, resulting in more reliable performance reporting. Demonstrated skills in mobile development and iOS development, focusing on precise timing and user experience.