I have a 45 minute technical presentation to a handful of people, technical interview with two people from the presentation, and then a behavioral interview with a couple additional people who were also at my talk

After a phone interview I was brought to their research center for an on-site. The interview process there included a presentation by me, followed by individual interviews with five people (one in HR). Mostly it was the form of STAR interview questions, though one person ignored them entirely. Only negative part was post-interview follow-up. I followed up with the hiring manager 3 weeks later, but heard nothing, then again a bit later, still nothing. Two months later I still haven't received the generic form rejection letter, or anything.