Our new mantra for managing and maintaining the health and functionality of our apps and environments is observability. Observability is the quality of software, services, platforms, or products that allows us to understand how systems are behaving. Without the new sources of data giving us insights, our modern cloud-native applications would be quite a challenge to monitor. Observability, that deep data, is the new fuel for our developer and DevOps engineers.
The duality of observability is controllability. Observability is the ability to infer the internal state of a 'machine' from externally exposed signals. Controllability is the ability to control input to direct the internal state to the desired outcome. While driving, observing a red stoplight means controlling our vehicle by pressing the breaks (or in some modern vehicles, having the brakes applied automatically for us).