“Dead bug style” circuit wiring is the cute name for soldering together components without a printed circuit board. The “dead bug” is the integrated circuit flipped upside down with its “legs” sticking up.
Over at the Dangerous Prototypes forum, a maker shows off his dead bug skills, which he used to solder a Little Wire:
My level of boredom was not enough to actually etch a PCB for it so I did a freeform version of it. With a fine tip on the soldering iron, 0.4 mm solder, a stereo microscope and a hour or two of soldering and bending wires even an old fart like me can get the parts together without a PCB.