Instrument your Go apps with Expvar and Datadog

The text discusses how to use the expvar package in Go to define variables that can be exported and published over http, allowing them to be exposed as metrics in Datadog. It provides a step-by-step guide on setting up an example application - a simple webserver that tracks the number of times a particular page has been visited in the last minute. The integration involves creating an expvar variable, defining the Datadog configuration file for expvar, and enabling it within the go_expvar.yaml file. Once set up, users can view the metric in the Metrics Explorer and use it to monitor their Go application performance.