How to Instrument Your Rails App with OpenTelemetry

Learn how to instrument your Rails application with OpenTelemetry in this comprehensive conference talk from RailsConf 2025 presented by an OpenTelemetry maintainer. Discover the fundamentals of observability and understand the benefits of OpenTelemetry's three core signals: Traces, Metrics, and Logs. Explore how Active Support Notifications work and how OpenTelemetry leverages them for automatic instrumentation, along with instrumentation strategies used in other popular Rails-related libraries. Follow along as the presenter demonstrates configuring the OpenTelemetry SDK in a minimal Rails application, adding custom instrumentation to core application methods, and exporting the results to an observability backend for monitoring and analysis.