Understandability is the most important concept in software, that most companies today aren’t tracking. Systems should be built and presented in ways that make it easy for engineers to comprehend them; the more understandable a system is, the easier it will be for engineers to change it in a predictable and safe manner. But with the rise of complex systems, it has become all too common that many times we no longer understand our own code once we deploy it.

As a result of increasing system complexity, developers are spending too much time firefighting and fixing bugs. In recent surveys, most devs say they spend at least a day per week troubleshooting issues with their code (sometimes, it can be a couple of days up to a full week trying to fix an elusive bug). This is hurting developer productivity and business results. It also creates a tough choice between flying slow or flying blind; as developers, we are too often making decisions without data in order to maintain velocity.

In this talk, I’ll highlight the importance of Understandability and how it has a huge impact on our day-to-day work. I’ll also discuss how it relates to more popular concepts such as complexity, observability, and readability. Finally, I’ll share some tools and techniques to manage and optimize for Understandability.