Interviewed with Niantic in February of 2021 through a referral. The interview process is very long, but the recruiters I worked with were informative, always quick to respond to questions, and always quick to schedule and communicate next steps.
Unfortunately they weren't able to hire me, but said they'd "keep me in mind", which they did, and a year later reached out again. I had a few more interviews, and then was given an offer.