Dotan Horovits's tutorial on Logz.io's Prometheus-as-a-Service metrics solution provides a comprehensive guide for setting up infrastructure monitoring using Prometheus and Logz.io. The tutorial emphasizes the importance of metrics in monitoring system health by quantifying data points related to application or infrastructure performance, such as CPU usage, which can signal potential issues requiring further investigation through log analysis. Users are guided through the process of activating a Metrics service account on Logz.io, configuring Prometheus to send metrics to Logz.io, and managing storage settings to optimize resource use. The tutorial also highlights the integration of multiple Prometheus instances for centralized monitoring and encourages users to explore visualization and analytics tools in subsequent tutorials, all while offering a free 14-day trial for hands-on experience.