Hackathons, the time-bound collaborative project-based competitions increasingly popular with undergraduate CS students, are both transformative and problematic. On one hand, they are unique opportunities to apply skills learned in the classroom to real-world, interest driven projects that celebrate risk taking, collaboration, and playfulness. On the other hand, they are often seen as exploitative, aggressively competitive, intimidating, and unhealthy events which promote CS worst practices while replicating and possibly exacerbating demographic-based inequity in CS. This dissertation presents in depth findings from a mixed-methods study of three hackathons to answer two research questions: first, do hackathons help students become better computer scientists? and second, are there differences in how people of different genders experience hackathons? Data included 318 pre-surveys, 80 post-surveys, 127 short interviews, 13 long interviews, 119 document artifacts, and survey answers from eight professors and 19 industry sponsors. Student participants ranged from high school students and graduate students, and were approximately 76% male, 22% female, and 1.5% other genders. A constructionism theoretical lens was used to understand the learning which occurs, and social cognitive career theory with stereotype threat was used to analyze gender differences. The results show that hackathons help students become better computer scientists by creating opportunities to practice collaborative making and take risks in a failure-friendly environment. While students were motivated to have their projects create a real world difference, it appears to play little actual role in how they learn or what they accomplish. Men and women both experience these benefits, although men find it easier to reach their goals for collaboration, and women identify more risks, which might account for the participation gaps. This dissertation offers many suggestions drawn from the data on how hackathons can both become more educational and more equitable. [The dissertation citations contained here are published with the permission of ProQuest LLC. Further reproduction is prohibited without permission. Copies of dissertations may be obtained by Telephone (800) 1-800-521-0600. Web page: http://bibliotheek.ehb.be:2222/en-US/products/dissertations/individuals.shtml.]