After applying online, I was contacted the next day and did a pair of phone screens, one with a recruiter and one with the hiring manager. After that, I was given a take-home assignment with a time limit of 8 hours. When they were happy with that, Procore paid for my travel to visit the Austin office and interview on-site, which consisted of 4 hours split between six different interviewers.
They had some really smart additions to the process, like starting off with the full panel to ask basic questions (without needing to repeat information in successive sessions). They provided an excellent guide for preparing for the interview, as well. But it was a little rough to go from 10am to 2pm without a break for lunch.
Overall, the experience was positive even though I didn't get an offer. The decision was made pretty quickly so I suspect there was a prospective internal candidate I was competing against, but I can't say for sure.
One word of advice to the Procore team: In this interview, the sheer positivity (and casual use of the future tense, i.e., "You'll be working with X team" "When you start, your first will be about Y") really made for some emotional whiplash when I got the call that they'd decided to pass on me as a candidate. If you're still evaluating multiple candidates or if you're anything but positive that you'll give the candidate an offer, please be mindful of these smaller elements. Job searching is an extremely opaque process, and candidates are looking at every piece of information they can get from prospective employers and potential coworkers.