How to observe your Blazor WebAssembly application with OpenTelemetry and real user monitoring

Observing WebAssembly applications presents unique challenges due to its design and execution environment. The Bytecode Alliance promotes standards and tools for enhancing security and usability, including better support for observability. Blazor WebAssembly allows developers to build interactive client-side UIs using .NET rather than JavaScript, leveraging full-stack capabilities of .NET on both server and client sides. OpenTelemetry can be integrated with .NET to provide comprehensive observability for these applications, but manual instrumentation is required for detailed visibility into backend operations. The project demonstrates how to instrument the backend with automated OpenTelemetry instrumentation and export telemetry data to an OpenTelemetry backend, such as New Relic. For the frontend, real user monitoring capabilities are available through the New Relic browser API, allowing developers to observe high-level telemetry from the frontend.