Online professional learning experiences can address K¬--12 computing teachers' need for content knowledge and professional communities. However, it can be difficult to design effective, large-scale experiences that reach broader audiences while addressing individual teachers' professional needs. We facilitated a two-week online professional learning workshop for 292 computing teachers, to support teachers in developing fluency with computer programming and broadening teachers' professional networks. In this mixed-methods analysis of teachers' participation, we drew on social network analysis methods to visualize the workshop community, examining the size and shape of the network. From the network analysis, we identified the 35 most influential participants and developed individual case studies to understand where and how participants engaged with the workshop. In this article, we share four cases of teachers with varying backgrounds, to illustrate how participation varied by teacher familiarity with the programming language and the professional community. We then consider implications for professional learning facilitators, around modeling community norms, maximizing flexibility of learning goals, and supporting participant connections. This article contributes to understandings of how to design a single experience that can address a wide range of teacher needs.