Intending to study Political Science, McCarthy initially attended Catholic University in Washington, D.C. but found herself drawn to the architectural studio.

[2] McCarthy held an administrative job in the early years of the Massachusetts Institute of Technology Media Lab, where she learned about computers.

“I was exposed to the most bleeding-edge technology and everybody in that environment had a point of view to add, whether you were a tenured professor, or, like me, a glorified secretary — it was all part of the mix.

This is where she saw her varied interests in technology, art, design, photography, architecture, film and theater come together in one discipline, projection design for theater.”[3] She has since gone on to work with a diverse group of notable directors including Leonard Foglia, Michael Greif, Kristin Hanggi, Andrei Konchalovsky, James Lapine, Joe Mantello, Michael Mayer, Dejan Miladinović, Mike Nichols, Jack O'Brien, Diane Paulus, Tim Robbins, Peter Sellars, Julie Taymor, John Tillinger and Rob Urbinati.

She recently designed Alfredo Catalani's La Wally[13] and Tchaikovsky's rarely performed Iolanta[14] for The Dallas Opera.

The production was directed by Leonard Foglia with Sets by Robert Brill, Lighting by Brian Nason and Costumes by David C.

[18] Late summer 2016 McCarthy designed projections for the New England premier production of Notes from the Field: Doing Time in Education, created, written and performed by Anna Deavere Smith in Boston at the American Repertory Theater (A.R.T.)

[36] In June 2019 McCarthy won a Betty Mitchell Award for Outstanding Projection or Video Design for her work on Everest at the Calgary Opera.

[44] The production was noted for its use of a fully robotic orchestra as well as McCarthy's utilization of Musion Eyeliner, which is a modern version of the 19th century Pepper's Ghost effect.