Most of my day is implementing functional flows but sometimes you need to work out what is happening behind the scenes. One example is workflow sometimes you get an stop error on the workflow and the message might not be too clear why it stopped. If you can take a backup of the database to a test environment you can debug there. You will need visual studio as the workflow code runs as IL under the AOS and you will also need to understand X++. Once you have these you can attach to the AOS and debug to see what might be going wrong.
Here is a quick overview.
AX2012 R3 CU11