Adafruit recently took on production of the Fadecandy project that Elizabeth Scott developed. The video above is How the Fadecandy LED Controller is Made using the automated PCB production machines. There are 3 basic machines in the equipment path, the panelized PCB goes through a solder paste machine where a laser etched stencil is used to put solder in just the right locations. The board is then moved through the pick and place machine where all of the components are automatically placed, and finally it rolls through a reflow oven where all of the parts are permanently soldered in place. Only thing to do after that is snap the board off and plug it into a test jig.