I did a video interview with Karat (contracted by Roblox). My experience was exactly like the one described by the another reviewer who did the Karat interview using C++. I had a working solution and the Karat interviewer explicitly confirmed it. However, Roblox rejected me without any explanation via a canned email. I had to email the recruiter and request feedback. I was informed that even though my solution worked correctly, they had other candidates who did better than me. My solution was not optimal not because I didn't know how to do it, but because I was short of time by 5 minutes. I think Roblox is looking for" Code Monkeys" who can regurgitate code at the drop of a hat. If you pause to think even for a few minutes (which is a natural thing to do if you are tackling a previously unseen algorithm problem), you will disqualify yourself. So if you are not a code monkey, don't bother applying because you will not be able to impress them. They are not looking for engineers. They are looking for robots who have the ability to churn out code without the need to think!