AT is short for Automation Test.  Last week, I finally begin to write a AT and get really excited about it since for a long time other colleges keep talking about it and saying it's hard to write one and don't know how to write one. 

It's important to understand why AT is critical to our project. It's because we need continuous delivery our project, but as our project growing big and complicated is nearly impossible to constantly test it manually so we left the job to AT. After using AT we can ensure our project quality through the whole development of our project and it's time-saving.