This program profile explains and illustrates a pedagogical application of Rhetorical Genre Studies (RGS) to a one-semester, upper-division online Professional Writing course. We explain our use of a heuristic, which we liken to "night-vision goggles," that enables students to systematically analyze field data that they gather from a participating worksite. We adapt an RGS methodology developed by Anthony Paré and Graham Smart to create our course heuristic and add a more explicit framework for investigating concepts of genre set, genre system, and activity system. We argue that our course design addresses transfer concerns by helping students develop meta-awareness, or specifically critical genre awareness, that they can then apply to future workplace writing situations.