At the developing world, it is necessary to know how the application that you’re working on is behaving, and the most known way of doing that is by metrics. They can be of several types, such as performance, product, or health. Nowadays, Prometheus is the market way for collecting metrics.
It is an open-source service maintained by CNCF , the Cloud Native Computing Foundation. It works like the following: an endpoint is exposed, and it responds with a desired body format. Then Prometheus calls this endpoint time to time, collecting all the information from there.