Android 15 removes the legacy PNG-based emoji font file (NotoColorEmojiLegacy.ttf) and only has the vector-based file. Developers need to update their apps, libraries, tools, and game engines to prevent compatibility issues with Android 15. Testing apps on Android 15 Beta 4 is recommended to check for functional or UI issues. New features in Android 15 include support for 16KB page sizes and private space support. Developers should take advantage of new platform features such as variable fonts for CJK languages and the ApplicationStartInfo API. Feedback on Android 15 features is encouraged during the beta program.