Is Airlineapps dot com the only route to apply with Delta?

I am very interested in Delta (and have been for years - didn't get a call during the last round of hiring) and am wondering if this is the best/only way to get my application and resumé to their HR.

I have been updating my stuff on airlineapps for years and have never heard a peep from a single carrier on there.

Any tips would be very welcome.