Received a generic rejection email (likely automated) after 6(!) rounds of interviewing. I received this email less than 24 hours before I was scheduled to do a company-wide presentation as part of the interviewing process. Did not receive any feedback from either the hiring manager or the HR rep despite dedicating 8ish hours of my time prepping, interviewing, and creating a presentation for this position.
Be prepared to dedicate 8-10+ hours of your time to this interview process prior to applying. There would've been a final round of interviewing after the company-wide presentation - thus, 8 rounds of interviewing in total.
The same position was then re-posted to a job board around 2 months after my rejection.