The majority of engineers either debug using print()/NSLog, or utilise debugger for po command and ordinary breakpoints. However, Xcode and its debug tools give way more power, starting from the LLDB command language and runtime breakpoints logging to Instruments for performance and CPU investigations. I will cover the best practices, talk about most recent changes from WWDC 2018 and show quite a few examples, where meaningless at a first sight error message can be expanded to a call to action using proper debug tools. By the end of the talk, everyone should learn how to debug like a pro.