Nancy Stewart was the first Black woman to be appointed vice president at IBM in 1991. Her R&D team developed the hardware and software for the market-leading 4381 computer system. She retired from the multinational technology company after 30 years.

In 2005, Stewart became Walmart's chief technology officer (CTO). She was also promoted to senior vice president, reporting to Linda Dillman, the CIO. It was the first time the retail giant had two women in such high-profile tech jobs.

As CTO, Stewart led Walmart’s systems, system infrastructure, and operations. Walmart’s 6,700 stores ran software and hardware from big data management companies and other major vendors. Stewart was responsible for over 11 mainframes supporting 2,000 processors, and two data centers in Bentonville, Arkansas.

Before joining Walmart in 2004 as vice president of large systems and infrastructure, Stewart served as a business services information officer at General Motors for three years.

Recognizing her impact and influence in the industry, Stewart was named one of the "Most Important Blacks in Technology" at the BEYA STEM Conference. She was cited along with 100+ Black industry leaders.