Applied online. Phone screening, followed by an invitation for an on-site. I have a "25 minute" seminar, but with audience questions it went for an hour and I still needed to skip some slides. Expect a thesis defense level of questioning. I interviewed with 4 different groups for 45 minutes each, with a lunch break with some newer members of the organization. I got a phone call notifying me of an incoming offer soon after, which I accepted.