It helps a lot if you know someone there, because they have thousands of job applications being sent at all times, and most applicants pretty much have similar qualifications. They almost always require prior work experience, so it helps if you work somewhere else for a few years, then apply to nationwide. They take a loooooong time to get back to you with their decision, because it's a huge company and there are many layers of management who have to sign off on new hires.