I applied months before I received my phone screen. The phone screen consisted of basic questions about the applied for field. Very easy, but at a significant time cost. The external interview consists of about half a day of meeting interviewers one at a time. They are given a small, standard sheet of questions, from which they will attempt to ask a question that a previous interviewer has not yet asked. Very easy interview to ace. The internal interviews have you sit down in a conference room with all of your interviewers who are, for the most part, subject matter experts. You must demonstrate knowledge of your field to gain their interest. They will also determine if you will fit well in their current group dynamic. This interview is somewhat more difficult, but still easy if you're worth your salt. Note: I interviewed here a few different times. Once, the interviewers expressed interest in hiring a person of my gender. I politely declined this job offer. This goes as a warning to prospective employees; Harris (the legacy company before L3Harris) emphasized diversity in the work place. While this is a good thing, this also gives programs disproportionate incentives to hire women and people of color. It is prudent for you as the interviewee to discern whether you value what you were born as or your discipline. I must recommend that you seek employers with similar values to your own. Be wary, because not all interviewers will be so clear in their intentions. You must be deliberate and ask the right questions.