Not at HashiCorp, but I try to respect applicants' time in interviews, and my overall process is less than 3 hours total for interviewing, across 4 people (all of which are self-scheduled). That said, when you have hundreds or thousands of applicants, people inevitably fall through the cracks unless you have an internal recruiting team entirely focused on maintaining that experience.
Interviewing sucks for everyone on either side, and efforts to improve candidate experience on my end have often been met with resistance in the company. One thing I've done is try to be as clear as possible at the end of interviews where someone stands. If it doesn't go well, I try to relate what didn't go well and how it applies to the position we're hiring for. If it goes well, my interviewers and I try to send out invites for the candidate to schedule the next interview within 10 minutes of completion, and I tell them that during the call.
So many companies are so risk-averse though, that they act like interviews are a poker game. I've generally had nothing but positives with my approach, and yes, someone may sue us at some point for being blunt and upfront, but my experience so far is people appreciate honest feedback if you deliver it kindly on the spot.