Measuring the availability, response time and behaviour of each and every business part is key to understanding the user journey. When a user performs an action on a digital business service, the application owner needs to know and therefore, if the service isn't working, the tech team and the support team also need to know. That's where application performance monitoring steps in. So, monitoring must evolve from just looking at hardware metrics to analyzing application codes and business transactions. The performance of an application should be measured with a user -centric view. This forms the basis of application performance monitoring (APM). To sum-up, application performance monitoring is the strategy and practice of continuously monitoring and tracking the performance of business applications and the user experience of end users as they access the applications to understand trends, isolate anomalies, and get actionable insight for problem resolution and code optimization.