This tutorial helps developers improve efficiency with Gatsby builds by using OpenTelemetry, an open-source project that provides performance tracing and monitoring capabilities. By leveraging performance tracing built into Gatsby, developers can collect telemetry data and identify inefficiencies in their build process. The tutorial shows how to set up the OpenTelemetry Collector, configure Jaeger, and analyze traces in New Relic One to gain valuable insights into build times and code changes. With this setup, developers can streamline their development time spent waiting for site builds and improve productivity. By using OpenTelemetry, developers can also measure traffic, track errors, and optimize build times for Gatsby applications.