Alejandra Lillo graduated with her first professional degree from the Universidad Mendoza Facultad de Arquitectura y Urbanismo, receiving her Architecture License in Mendoza in 2000. Her architectural career began as a designer at Corbett Cibinel Architects in Winnipeg Canada in 2001, where she focused upon healthcare and educational design. In 2003 she pursued her second professional degree, a Masters in Architecture, at UCLA's AUD, graduating in 2004. She joined the Los Angeles office of Graft as a lead designer and project manager in 2004. In 2007 she was promoted to the position of Managing Partner and CEO of Graft Inc.

In February 2011 Alejandra co-founded Undisclosable with Bryan Flaig.

She and her team have produced architectural solutions for a wide variety of project types, including healthcare, commercial, residential, cultural and hospitality, maintaining a flexible and often cross-disciplinary attitude in order to create progressive, nimble solutions within a rapidly changing world. These designs espouse the belief in enriching spaces through combining seemingly disparate elements, whether they pertain to the narrative sequences contained within a building, geometry, or materiality. Recently, Alejandra has aggressively participated in philanthropic enterprises, including Make It Right with Brad Pitt, WM+P, and Cherokee, where Graft sits on the Board of Advisors. Located in New Orleans' Lower Ninth Ward, this work was the centerpiece of the 2009 Clinton Global Initiative.

Alejandra's work has been widely published and exhibited at the A+D Architecture and Design Museum, LACMA, UCLA, Stilwerk Design Gallery Hamburg, Aedes Gallery Berlin, The Chicago Athenaeum: Museum of Architecture and Design, The School of Architecture in Florence at the SESV Santa Verdiana, The European Centre's Contemporary Space in Athens Greece, and the Biennale Architeturra in Venice.

Under Alejandra's oversight, her team has produced award winning hospitality design projects at The Bellagio, The Mirage, The Monte Carlo, and most recently the Aria Resort and Casino for MGM Mirage and The Light Group. Other project clients include: W Hotels Worldwide, Starwood Capital, The Moinian Group, Citizen Watch Company, JUXT Interactive/CISCO, Volkswagon, Sci-Fi/NBC Universal Television, Kanera, Midnight Oil, DC Shoes, Quiksilver, Orix Corporation, Hallier Investments.