At New Relic, there is a growing trend of customers adopting OpenTelemetry for observability, particularly in serverless environments like Azure Functions. The guide outlines how to instrument DotNet Azure Functions with OpenTelemetry for comprehensive visibility in New Relic, emphasizing the separation of the Azure Functions Host and the .NET Isolated Worker process, and detailing the configuration of the OpenTelemetry SDK. It highlights that the integration of OpenTelemetry, currently in preview, supports specific triggers and enables the export of telemetry data to any compliant endpoint, including New Relic's. Key points include the importance of the telemetryMode setting in host.json for emitting function invocation data as OpenTelemetry signals, and the need for configuring appropriate packages to align with specific OpenTelemetry requirements. The guide also discusses the automatic collection of standard metrics for HTTP requests and the normalization of this data by New Relic to enhance the APM UI experience. Additionally, it provides guidance on configuring telemetry data export destinations and addresses sampling configurations to ensure effective data processing and trace experience.