Completed 3 rounds of interviews and made it to the final round. Seemed very positive at first and was excited to continue. They canceled the final interview (over a week out) via email with no context, then a few hours after follow-up sent - they stated they hired someone already. Also provided a reference, but they had another uninvolved employee (not in TA or HR) complete backdoor reference checks and didn’t show up for the call with actual reference provided. This is a terrible hiring practice given you can receive biased information, uncredible sources, and most importantly, breaking candidate's trust. Not a great way to start any new business relationship.