HR called to confirm I understand the details of the work (e.g., internship ends without immediate conversion to FTE, salary expectations, etc.), then scheduled a 30m hiring manager round for the next day: "some behavioral, some technical". 30m hiring manager round was actually a 60m interview, 30m behavioral then 30m technical. Good behavioral questions, very friendly and professional. The technical was high level questions on the stuff I spoke about in the behavioral by a tech lead. One week later I got a call from HR saying they would like to conduct another round with a director. Not clear whether it was behavioral or technical. Director round was behavioral but they were so friendly you wouldn't know they were asking behavioral questions. Probably trying to gauge if you're really in alignment with the role. One week later I heard back from HR saying they'd like to extend an offer. Throughout the process I'd call my HR representative to check in on the status of my candidacy. Everyone I spoke with was very professional and friendly, which reinforced my excitement for this opportunity.

The interview was comparatively easy. They went over my resume first and my PhD research. Then asked basic questions about wireless communications and digital signal processing. the questions were not very hard but requires clear understanding of the topics.