This conference talk from SREcon25 Americas explores how traditional network engineering techniques based on graph theory remain highly relevant for modern cloud infrastructure. Learn how to apply these "lost arts" to today's distributed service-oriented architectures as Steve Dodd from Slack demonstrates methods for building network traffic attribution at the service level without expensive vendor logging solutions. The presentation bridges classic network engineering approaches with contemporary cloud environments, showing how graph theory provides a visual and quantitative foundation for analyzing network behaviors, optimizing data flow, routing, and enhancing resilience in complex topologies. Discover practical techniques that can deliver significant benefits when applied to large-scale cloud infrastructure.