Why does it take sooooo long for railroads to get back to applicants?

Going back from what I had went through, why is it that other jobs are able to tell you within a few days or a week to tell you whether or not you got the job but with railroads, it can take 2-3 months. Many large companies or corporations use the same job application software, do the same assessment tests on their candidates, use the same technology that kicks out unqualified candidates out the system as the railroads do, yet railroads are pain stakingly slow. What exactly do they do with the applcations? It cannot be blamed either on the volume of applicants either because I bet there are some places that get way more applicants for one job than the railroads do.