In a 2011 Design Taxi article titled "Design Anthropology: A Coming of Age," Rachel Xu wrote that Design Anthropology found its initial impetus in the dot-com boom of the nineties. Incessant developments in technologies in that decade meant little time was available to train young designers to understand the context in which their work was being developed for. Designers who possessed more than just a creative flair then began to apply their craft and knowledge to different—and bigger—fields.

Tunstall began her professional life in the nineties defining user experience and strategy at Chicago-based E-Lab, where she "undertook ethnographic anthropological research on everything from men’s grooming to community use of telecommunications." Tunstall's social sciences training was valued among interactive and product design firms aiming for a more rigorous approach to user experience and research. E-Lab was an experience-based research firm, leading a new marketing philosophy with a direct approach: Understand how real people experience real products to create innovative product concepts and services.

The idea challenged companies to forget conventional market research (focus groups, consumer surveys, targeted test markets) because a breakthrough approach has tapped into the consumer behavior patterns that drive everyday purchasing trends. E-Lab pioneered that breakthrough. Cambridge-based Sapient Corporation, an IT provider and e-services consulting group for Global 1000 companies and startups, acquired E-Lab in 1998. E-Lab became Experience Modeling, one of five strategic disciplines that Sapient incorporated into its organization. Tunstall was a Sr. Experience Modeler, for Sapient Corporation from 1999 to 2002 then moved on to Arc Worldwide, a Leo Burnett/Publicis Company where she was a Sr. Experience Planner from 2003 to 2005. At Arc Tunstall immersed herself in hardcore advertising and marketing furthering expanding her range of experience and insight.

After the turn of the century Tunstall focused on academic and civic-minded pursuits. In 2005 Tunstall became Associate Director, City Design Center, University of Illinois at Chicago and Associate Professor of Design Anthropology, School of Art + Design, University of Illinois at Chicago and began her career as an academic leader. From 2005 to 2006 she also served as the managing director of Design for Democracy, an ongoing AIGA program that applies design tools and thinking to "increase civic participation by making interactions between the U.S. government and its citizens more understandable, efficient and trustworthy. Design for Democracy collaborates with researchers, designers and policy-makers in service of public sector clients and AIGA’s goal of demonstrating the value of design by doing valuable things."

In 2008 Tunstall organized the U.S. National Design Policy Summit and Initiative focused on creating an actionable agenda of U.S. Design policy for economic competitiveness and democratic governance. In 2009 Tunstall became associate dean of learning and teaching, Faculty of Design, and associate professor of design anthropology, Faculty of Health, Arts, and Design at Swinburne University of Technology in Melbourne, Australia. In 2010 Tunstall found the Cultures-Based Innovation Initiative focused on the use of tangible and intangible cultural heritage to drive irreversible changes in peoples' attitudes, behaviors, and/or values that directly benefit communities under social and environmental distress.

In October 2022, Tunstall was honored the Education Award at the
Black Artists + Designs Guild (BADG) in New York City.