Had an initial screening call with their HR rep. About 2 weeks later, I had an hour-long interview with the Hiring Manager, and 2 days later I had another hour-long interview with a VP and another employee.
I thought all the conversations went well, but then I was hit with radio silence. I reached out, and they said they were delayed because someone went on vacation for a week. I reached out again the following week and they told me they weren't ready to make a decision on who they were moving forward with, but they'd let me know when they do. I never heard from them again, until I was sent a boiler-plate rejection email 4 months later.
It is completely unprofessional to spend 2.5 hours interviewing someone and not have the decency of reaching out to reject them on the timeline the company provided. Serious waste of time and a very inconsiderate hiring team.