There were a couple of rounds of phone and video interviews. Overall, pretty easy questions, no tricks, they just want to get know you and your skills and lay expectations.
I wasn't impressed with the interview process and some things that were mentioned to me raised red flags. Not being able to be accommodating schedule wise was a big one. Unfortunately C3 is missing the mark when it comes to work-life balance and expect you in the office from 9 to 6, no exceptions. They even mentioned to me on the phone verbatim "If you want any work from home or schedule flexibility, go work for companies such as Google and Facebook." This definitely threw me for a loop. I wanted to make sure that not only was I a good fit for the company, but the company being a good fit for myself and C3 did a terrible job trying to convince me. The interviewers couldn't talk very well to company culture and pushed back on a lot of my questions.
To me, I got the sense they did not really care about the mental well-being of their employees and are only focused on getting the job done.
Even if an offer was extended, I most likely would have declined it. The company, even though relatively new, is stuck in the old ways of how companies operate.