As society increasingly relies on computers to drive social, economic, and political decisions, it is essential that the computing workforce reflects the racial and gender diversity of the larger population. This experience report presents CompSciConnect (CSC), a multi-year program designed to broaden participation in computing for students from historically excluded populations (girls and/or Black, Latina/o/e/x, and Native American [BLNA] students). Each cohort of CSC participants span three years with participants meeting for two weeks in the summer and one weekend a month during the school year. Students progress through three levels of the program: Yellow (beginner), Red (intermediate), and Terp (advanced). Quantitative and qualitative data guided the growth and implementation of CSC. CSC began in 2012 with just 14 students and now reached over 532 students today. Additionally, CSC alumni attribute their experiences in CSC to their decisions to major in a computing field. Various design factors–such as community-centered student recruitment strategies, the long-term structure of the program, and the scaffolded curriculum–contributed to CSC’s growth and its positive impact on CSC participants. In this paper, we present CSC, elaborate on the design factors that led to CSC’s success, and highlight the challenges and major lessons learned throughout CSC’s development.