Exposing metrics through the metrics HTTP endpoint is the de facto standard when it comes to exporting application metrics in the cloud native universe. But did you know this well-known pattern can be used for more than just collecting metrics? This talk will show how instrumenting applications can be leveraged to improve your experience with end-to-end (E2E) testing. If your application is already instrumented for collecting metrics, why not take it a step further and use the exposed data to bring your E2E testing to the next level? This has the enormous benefits of giving you detailed insight into the state of the tested application and allows for more complex testing scenarios, which are not possible without observing the behavior of an application from the inside. The talk will also describe how this framework has been employed in several open-source projects, including Thanos and Observatorium, and what benefits have been gained from the change.Click here to view captioning/translation in the MeetingPlay platform!