In this chapter, we learned about the basics of PromQL, from selectors to functions, covering concepts such as binary operators, vector matching, and aggregations. Going through the common patterns and pitfalls, we were introduced to how this language allows much more than simple querying and how it has become an essential infrastructure tool, helping with the design and management of SLIs and SLOs. We also demonstrated several scenarios where PromQL shines, and how seemingly complex queries are not that complex after all.

In the next chapter, Chapter 8, Troubleshooting and Validation, we'll delve into how to validate a healthy Prometheus setup and learn how to troubleshoot issues quickly, ensuring the stability of the monitoring stack.