Listen very carefully. If you come here, or to any 121 class, without a solid knowledge of turbine systems, you will drown. They're not gonna sit down and explain to you what a turbine engine is, what a stator vane is, what a 10th-stage bleed is, et cetera. You're expected to know it cold. I don't mean that you're expected to know the airplane (that's why they have Systems, which we are currently enduring), but you'd better have a very strong foundation of instrument flying skills and generalized turbine systems knowledge. If you come here and ask "What's a pack?", nobody's gonna be able to help you.

Sure, Mesa might hire you with a phone call. But getting hired is merely step 1 on a very long journey. All that the job offer means is that you've now earned the right to bust (or pass) your:

Indoc exam
Systems exam
Maneuvers validation
Procedures validation
Knowledge validation
LOE
IOE

With the exception of indoc and IOE, all of those are PRIA-reportable events. Bust one of those, and you'll have even more checkride failures following you around.

In other words: if you're insulted by the types of questions you get asked in a 121 interview...perhaps you're not ready for a 121 interview.