Jeff Zhang focused on modernizing build systems for Android libraries, working across the AzureAD/microsoft-authentication-library-common-for-android and AzureAD/microsoft-authentication-library-for-android repositories. He upgraded Gradle and the Android Gradle Plugin to version 8.1.1, updated the JDK to 1.17, and introduced namespace properties in build.gradle files. Using Java, Gradle, and XML, Jeff realigned build configurations and CI/CD pipeline tasks to support the new toolchain, improving build performance, security, and compatibility with current Android tooling. His work reduced future maintenance risk, enhanced onboarding for new engineers, and prepared the codebase for smoother future upgrades, demonstrating depth in build system configuration.