Getting an interview at Lockheed Martin is all about knowing someone or just getting lucky. I happened to be in the former camp and was invited to a hiring event fairly quickly. You can apply online and hope for the best as well.
The interview itself is super easy. I met with my direct manager, his co-manager, and their manager. They didn't bother asking anything too technical, but I did talk about some languages and frameworks I found interesting. Most of the interview just them making sure you're the right fit so just make sure you come across as a hard worker willing to learn.
Getting an offer takes forever thought because the HR team is super slow and you have to keep prodding every few weeks. Interviewed in early December and got the offer in early February to start working immediately.