Originally Posted by
Rookhawk
It appears some smart people used a combination of scripting languages phantomjs, cron, python, etc. to create an auto-search for new appointments at Global Entry.
Some use plugins to help them getting earlier appointments. Many of us do it the old fashioned way by doing new searches every five minutes or so. With new slots open at many locations, even cancelation rate remains the same, more close in slots should become available if you are persistent.