The original hiring program was started by a consulting group run by a Carl Hoffman. If you want a little insight into the philosophy you can read his book Calculating Success, How the New Work Place Analytics Will Reviatalize Your Organization.

Cliff notes: Delta only hired military pilots but knew they would soon have to hire civilian pilots. Hoffman offered a program to filter pilots, collect data and adapt the hiring program to improve the quality of pilots accepted by Delta. Under this program pilots hired were supposed to have their training data (through out their career) collected and if issues occurred, the data was to be cross referenced with metrics from their interview/hiring process. The goal to collect data and identify deficiencies that could be identified before ever hiring future pilots.

The Hoffman group has been contracted by a few other Major Airlines, I know of one Cargo Carrier and a few DCI carriers became involved to.

IMHO the challenge we see is the balance between hard data collected thru testing and the human factor issues. The interview team's biggest challenge is that they are human. No one is perfect and they bring their own expectation bias, beliefs, fatigue, etc to the interview room.

We've all seen it every Air Carrier, pilots who you'd think had no business in the cockpit get hired. Then pilots who are top notch and well respected, never even get a call or worse told no. Anecdotally pilots that I spoke with at a cargo carrier who use the Hoffman group told me that the new hires are cookie cutter pilots. They're all the same and it was driving most pilots nuts. Maybe a little human error and chaos leads to some diversity to the Pilots hired at Delta. But we really need more diversity here compared to other airlines.

Face it's very challenging. If you're a regional puke getting even one legacy interview is the "golden ticket" (face palm). American has the flowthrus and military, Delta mainly hires military, United is more diverse IMHO. But you gotta jump thru the damn hoops if you want to get on easy street (compared to the regionals). Take on the extra responsibilities if you can at work. Do the volunteer work. Prep Prep Prep. Utilize the professional Prep companies. I don't care what anyone says, you cannot be over prepared. Unless your name is Tony Robbins. It's the same damn job, same passengers, same paint on the plane but with better pay, respect and fleet opportunities. Same damn job.