This conference talk explores the journey from sampling-based tracing to achieving full visibility across trillions of spans. Learn how to overcome the limitations of traditional sampling methods that miss critical edge cases and leave users frustrated despite "green" system indicators. Discover the process of migrating from Zipkin to OpenTelemetry (OTel) while maintaining cost efficiency and enabling 100% sampling for critical flows. Explore how developers can gain a comprehensive 360-degree view of service and API performance using OTel to identify RED (Rate, Error, Duration) metrics and diagnose issues faster. The presentation also addresses backend challenges in scaling OpenTelemetry, including managing high data volumes, optimizing storage, and improving query performance, while comparing various open-source tools and approaches.