This post, the final in a three-part series on monitoring Varnish, details using Datadog to integrate and visualize Varnish metrics, ensuring continuous and effective monitoring. It begins by verifying the proper functioning of Varnish and varnishstat, followed by installing and configuring the Datadog Agent to collect and report metrics. The setup process includes creating a configuration file, restarting the Agent, and verifying integration success. Once the Datadog Agent is operational, users can access a Varnish dashboard for key metrics and create custom dashboards by adding other relevant metrics. The post also guides setting up alerts for specific metrics, such as Varnish’s dropped client connections, using threshold-based alerts to notify teams via channels like Slack and PagerDuty whenever metrics exceed predefined values. The goal is to enhance visibility into web infrastructure and automate alerts tailored to specific organizational needs, with a call to action for those without a Datadog account to sign up for a free trial.