I founded Dark Matters in 2022 to make astronomy accessible across language barriers. I grew it from zero to 10,000+ subscribers across 10 school and university campuses in 12 months with no paid marketing. I ran growth experiments across 4 channels (WhatsApp, Instagram, campus print, and email) and identified WhatsApp forward loops as the highest-retention channel, 3x better than Instagram. I pivoted strategy mid-cycle based on that data. I also managed a 13-person editorial team across 3 time zones, and 20+ reader interviews led to a permanent format change and shorter explainers outperformed long-form by 2.4x on forward rate.