I had a bad experience with Contingent and their hiring process. I had 3 calls with them and on the final one, with the CEO and someone heading the team I'd be joining, I was told they were going to make me an offer. This didn't happen. And it would have been totally fine, it still was the last stage interview and if there was a reason I wasn't a good fit, that's totally fair and acceptable.
What is not acceptable is that after this last interview I was just ghosted, and never heard back from them. I find this very unprofessional. They present themselves as a company that cares about their employees, but if then they treat candidates like this, it is certainly not a good sign.