Hackathons provide rapid, hands-on opportunities to explore innovative solutions to problems, but provide little support to teams in moving those solutions into practice. We explore the use of post-hackathon Learning Circles to connect hackathon teams with key stakeholders, to reflect on prototypes and consider business models. We conducted a qualitative field study with 4 post-hackathon teams on the theme of technology, social isolation, and aging. Our results show that Learning Circles are an effective way to involve stakeholders early in the development process, and to develop a deeper understanding of users, markets, and technology.