Google has begun promoting INP (Interaction to Next Paint) as a Core Web Vital metric, which may impact SEO rankings if users experience slow interactions on websites or apps. To identify the root cause of these issues, developers can use various methods such as comparing JavaScript self-profiling with other browser APIs. Real user monitoring is key in pinpointing performance issues and gathering valuable data for attribution. LoAF (Long Animation Frames API) provides script attribution information, which helps narrow down the attribution problem, while JS Self Profiling allows developers to programmatically start a profiler during user sessions in production, revealing slow functions and their locations. By combining these tools with real user data, developers can efficiently diagnose and fix performance issues, improving both load times and user experience.