Very easy. They only interview when they are looking to fill positions. They are required to keep applications on file for some time but may not call you if they are not hiring.
If looking to hire and you catch their eye, they will invite you in for a math test. The test covers basic addition, subtraction, multiplication, and division. Some questions are basic and straightforward while others are complex and require thinking.
If you pass the math test, then they will call you in for an interview in their conference room. They will ask you basic questions about you, your past work experience, and you are then given the opportunity to ask any questions you want.
Let's they say they like you, then they will ask you to take a drug test and submit to a background check.
Assuming you pass everything, then they will extend a job offer.
It took me literally 4 days until an offer was extended (it may take up to 1-2 weeks before you hear anything back).
If you are offered a job, don't just accept right away. Take some time to think about it! If you've never been to a QT before, then I'd suggest going to one and watching these guys in actions because they are the REAL DEAL! They hire the BEST of the BEST and it shows!
Again, if you are offered a job, then congratulations! Best of luck and I hope you enjoy your experience. Although I did not last long for my own personal reasons, I will not say anything bad about them.