Also recommend Ready Set Takeoff for the technical and COG prep. Got a CJO last week at FDX (and hoping for one with DAL this week) and the testing portion was almost a non issue thanks to this prep!
If you want to land the coveted Delta CJO then make sure you focus on what matters. The two best services I recommend are Emerald Coast and Ready Set takeoff for the cog/test. If you are an Emerald coast client you can sign up for Ready Set Takeoff through their website at a cool discount! These prep services will help you navigate through one of the hardest interviews in the industry. Could not have done it without them!