Navigating through Legacy Applications like a Pro

A comprehensive guide to understand the complete application function call chain and logging the slow functions

Switching to a new company is always exciting and everyone wants to do their best at creating a new application or working with an existing one. Existing applications can be a bit too much at times, the legacy code too overwhelming to go through. A smart developer would not only complete the tasks assigned to him/her, but always look for some improvements in the existing code while doing their job.

Are you gonna tell me about refactoring??

NO!!, strictly no. Refactoring a legacy code on your own, without a plan will not yield the results you’re expecting (at least for me it never did). This article tells you how to become a pro at knowing what are the Pain Points(Slow functions) as well as the complete call stack of an application in developer friendly ways.

A bit of background

Imagine that you have been given the task of writing a new API, which uses some existing functions from the application. You start writing the API, you do a great job of writing extremely optimised code, but when you start testing your new API, you see that the…