From Zero to Metrics: Open Telemetry + Prometheus + Grafana in a .NET Web API in 7'

Description

Learn, step-by-step, how to add OpenTelemetry metrics to a .NET 10 C# Web API, scrape them with Prometheus, and visualize them in Grafana. We use the default template app so you can focus on the core flow: instrumentation, collection, and visualization. What you’ll do: - Create a fresh Web API project - Add OpenTelemetry packages & minimal configuration - Expose metrics for Prometheus scraping - Run Prometheus and point it to your app - Run Grafana and build a simple dashboard (4 panels) Signals covered: counter + histogram (via built-in ASP.NET instrumentation) Prerequisites: - .NET 10 SDK installed, - Prometheus standalone zip file: (https://greekdeveloper.com/dl/prometheus) - Grafana standalone zip file: (https://greekdeveloper.com/dl/grafana) Repo: https://github.com/greek-developer-courses/observability-intro-metrics Blog post: https://greekdeveloper.com/posts/2025/csharp-metrics-grafana-prometheus Next episode (teaser): Logging with OpenTelemetry (coming soon!) Clone the repo and experiment. Link & Subscribe for the tracing + logging episodes. ### Hashtags #observability #opentelemetry #dotnet #prometheus #grafana #metrics #webapi ### Chapters 00:00 Intro 00:20 Solution layout 00:47 Creating a new webapi 01:17 Adding Opentelemetry 02:46 Configuring & Running Prometheus 03:34 Configuring & Running Grafana 04:10 Creating the Dashboard LinkedIn: https://linkedin.com/company/greekdeveloper