This document discusses challenges and lessons learned from building a native advertising platform. It covered trying separate, hybrid, and combined approaches for sponsored and editorial content. Key challenges included weak storytelling tools, complex technical changes, and data discrepancies across systems. The lessons were to create a common definition of native, experiment aggressively by not architecting from scratch at first, and to invest heavily once successful approaches are found. It also recommends building native directly into applications for benefits like no ad blocking and low latency.