What browser profilers teach us about Javascript

Profiling is commonly associated with performance optimization, but its applications extend far beyond that. One other use case of profiling is that it can help you understand how a language works. In this talk, I will use browser profilers such as the Chrome Profiler to show many insights into the internal workings of Javascript. For example, what can the profiler teach us about timeouts, Promises, the event loop, generators, etc?