Leveraging observability to build better applications
What is observability?
The concept of observability dates back to the mid-20th century, where it was originally used in control theory to describe how the internal states of a system can be inferred from knowledge of the system’s external outputs. While the term is still used in the mathematical context, today it is commonly used in the context of infrastructure, service, and software application stacks.
Software systems are usually designed and described with certain functional requirements that specify what the software should do. These might include specific interaction or user stories, like “when a user enters a valid user ID and password pair, they should get logged in.” Or they might be a little more specific, such as “if an item has zero stock, it should not be able to be put in a cart.” These requirements might not all be written down in the same manner that they would have been when software development followed a strictly waterfall approach, but rather implemented as tests in test-driven development or agile approaches; however, the requirements are still there.