This project focuses on youth-centered, culturally-relevant, out-of-school educational research and development. The team includes learning scientists and researchers, educators, directors and program administrators from Upward Bound and a makerspace/informal science institution, and engineering and wearable technology industry professionals. The STEM emphasis centers at the intersection of engineering and computational sciences, with content around coding digital technology and microcontrollers, and designing, developing and fabricating wearables and integrated systems. The project uses an iterative, design-based research methodology to lay the groundwork for design principles and empirical research findings on the relationships among curiosity, computational thinking, and STEM careers. It further provides feedback on how to foster equitable, out-of-school STEM secondary education, and informs broader STEM enrichment efforts at multiple Upward Bound sites nationally. The project has four objectives: (a) Testing and refining the STEM and arts-based curriculum, which includes hands-on, project-based activities; (b) Building design principles around the linkages between curiosity, computational thinking, and STEM careers; (c) Solidifying a research-practice partnership with learning scientists, educators, makerspaces, summer programs, and youth-serving organizations; and (d) Broadening underserved students’ participation through summer camps and school-year activities.