General Atomics Entry Level Software Developer interview questions

Received a phone interview. I Was asked basic concept-based questions related to Object Oriented Programming and embedded systems. The interviewer wanted to know if you had a good understanding of programming basics. He was a bit hasty, though. One question that I needed to think through was "what is an interrupt and what are the steps necessary to take it". I asked the recruiter if I could have a moment to think it through and he responded with "you either know it or you don't" and rushed me to move on to the next.

I got a phone interview to get to know my background. Then I went in for a 3 hour interview. They showed me around but I got the feeling like they weren't really interested in hiring me. Only the first interviewer was actually there. One them didn't; show up and the other said he was to busy to interview me so they found to random people to talk to me and they told the second of the two that when they were done total me to the lobby. The second interviewer didn't know what to ask me. The only reason he even asked me anything was because I had brought copies of my resume and he just asked me basic questions from there. When the last one finally showed me to the lobby I wasn't told about any follow up or when they would get back to me. I was really disappointed by how they made me feel. They should have just told me I wasn't a good fit from the begging instead of making me talk to them for three hours. Know you pointers and how static variables work. Only two technical questions throughout the whole three hours. Three weeks later they called me just to tell me I didn't get the job. I don't know why they would call me after three weeks.