MITRE first conducts an informal interview with a program lead where they ask some informal questions in a laid-back virtual setting such as: "Do you see yourself tackling several projects at once or focusing on one?" "What do you know about us?" "Why do you want to work here?" After this, if they pursue you further, you'll present on a topic of your choosing to a panel of about 4 professionals, answer technical questions, and have an informal chat after the official items. The interviewers were professional and approachable.