4 rounds; 1 round with external hr, 3 round 1hr each with 2 team members. Had my reference check. The process took more than 1 month. Regular behavioral questions with strong focus on research questions and asked about my writing samples. After the final round, asked for my reference. The tricky thing was here: I thought I almost made to an offer, but guess what, after getting my reference checked, waited for 3 weeks to get an rejection letter. Kept telling me that I was still being considered, but i guess i was just getting waitlisted. Wish they didn't hang me there for that long.