Discover strategies for fostering cross-community collaboration in open-source projects through a 32-minute conference talk by Ke Wang from Meta and Bin Fan from Alluxio. Explore their experiences and lessons learned from collaborating on a joint feature between the Presto and Alluxio communities. Learn how to overcome non-technical challenges magnified by inter-community projects, including building leadership confidence, resolving debugging issues within regulatory frameworks, managing cross-project release dependencies, and maintaining progress during the COVID pandemic. Gain insights into prioritizing collaboration, navigating tight timelines, addressing release cycles and bug escalations, establishing effective communication channels, and handling responsibility shifts. Understand the core challenges of caching data at Meta scale and managing incidents in large-scale collaborations.