Developed a performance-oriented enhancement for the dropbox/AffectedModuleDetector repository by implementing a Selective Build configuration that skips building all projects when no changes are detected. This feature, built using Kotlin and focused on software configuration, aimed to reduce continuous integration time and resource consumption. The approach included updating both documentation and unit tests to ensure the new behavior was clearly communicated and reliably validated. By aligning test coverage with the new configuration, the work improved maintainability and reliability of the testing process. The solution demonstrated a methodical application of configuration management and test-driven development principles within a Kotlin-based codebase.