Joan Margaret Winters began working in Computer Services at Cornell University in 1970. She later became Coordinator for User Support, a position that included managing the office's consulting and educational functions. While at Cornell Winters also designed and implemented SPINDEX II applications for the Department of Manuscripts and University Archives. In 1980 Winters took a position as a scientific programmer in SLAC Computing Services at the Stanford Linear Accelerator Center.

In the mid-1970s Winters became active in SHARE, an International Business Machines (IBM) computer user group. In 1976 she joined SHARE's Human Factors Project, a group dedicated to educating members of SHARE and employees of IBM about the importance of human factors in the design of hardware and, especially, software and conducting research into human factors and software appraisal tools. Winters became deputy manager of the project in 1978 and served as project manager from 1983 to 1987. She also served on the Interactive Systems (INTERSYS) Task Force from 1979-1982 and was a primary author of the task force's report. She became vice chair of the ASCII/EPCDIC Committee (later, a task force) in 1987 and manager of the Integrated Technology Group in 1988. Winters also belonged to the Human Factors Society and the Association for Computing Machinery.