Nationally, women are greatly under-represented in STEM (Science, Technology, Engineering, and Mathematics) postsecondary majors. Intersect race, social class, and gender, and low-income girls of color enter technology fields at a lower rate than White middle-income females. The authors created an after-school and summer program, CompuGirls, framed by heuristics that encourage academic and professional achievement. In this article, they describe how the CompuGirls curriculum integrates social justice with computing, thereby encouraging learners to design for diversity. (Contains 3 figures.)