It is pre-compiling apps from java to native executables. This comes from the ART runtime which is the default in Lollipop and newer. Google for "android ART"
I think this is a HUGE problem, and that somebody is going to die because they're unable to call 911 while the phone is "optimizing"
I think this is a HUGE problem, and that somebody is going to die because they're unable to call 911 while the phone is "optimizing"