Datadog has created various integrations with popular applications, allowing users to instrument their custom apps using DogStatsD libraries and the RESTful API. For developers writing in Go, Datadog Agent 5.1.0 introduces the ability to use expvar, a Go package that allows variables to be exported and published over HTTP. By following simple steps, developers can expose an expvar as a Datadog metric, enabling real-time monitoring of their application performance. An example using a trivial web server demonstrates how to define an expvar variable, create a counter, and set its value, which is then published to a standard location by the expvar package. The final step involves enabling the Datadog expvar configuration, allowing users to monitor their Go application performance in the Metrics Explorer.