Circle Internet Financial interview questions

A recruiter contacted me via LinkedIn. The process took 2 months. I spoke with the recruiter on the phone, covering the basics (resume, interests, opportunities at Circle). Some time passed, but eventually they set up a meeting between the director of engineering and I. I met, one on one, with the director of engineering via a video conference. The conversation remained high level, focusing on a discussion of what their engineering strategy was and did not involve a coding exercise. Overall, I think this discussion was rather positive. I was given a fairly large, take-home, systems architecture assignment. It took about 20 hours to code, test, and document as required (an incorrect solution can be done much quicker). I delivered this to them and, via yet another recruiter, moved onto a one on one phone interview with their CISO. This conversation went south very quickly. Within a few minutes (also based on videos on the internet), I got the impression that this individual has been simply winging it for decades and understood very little about security. If I had to guess, I presume that the vast majority of their education here comes from those spammy IT security websites, but were grossly misinterpreted. I have not ever met someone I have as little faith in as this person. It is to the degree that I am genuinely concerned about the security of their platform/products. We ended up agreeing to end the call early and I declined to consider additional roles at this company. There would be too much risk involved otherwise. Overall, this process was pretty disappointing. The unpaid take home assignment was too large to justify its spot as early on in the process as it was. It would have been better to discover that there was not a fit (based on who is working there) earlier in the process before having to commit as much time as I did.