The Jargon File (version 4.4.7, 29 Dec 2003):

polygon pusher
 n.

    A chip designer who spends most of his or her time at the physical layout
    level (which requires drawing lots of multi-colored polygons). Also
    rectangle slinger.


The Free On-line Dictionary of Computing (30 December 2018):

polygon pusher
rectangle slinger

   (Or "rectangle slinger").  A chip designer who spends most of
   his or her time at the physical layout level (which requires
   drawing *lots* of multi-coloured polygons).

   [Jargon File]