A tech screen is a just that. It's not meant to accurately reflect the problems you work on, it's meant to see whether you can actually write code, whether you

A tech screen is a just that. It's not meant to accurately reflect the problems you work on, it's meant to see whether you can actually write code, whether you can explain your reasoning, and just generally how you react to a problem that requires some level of abstract reasoning. It's a way of filtering out candidates. At most companies, that's 30 minutes out of the 5 hours of interviews you're going to go through. Cloning a directed graph seems like a perfectly reasonable interview question. It requires no specialized knowledge, just being able to navigate a fairly common data structure. I can't imagine a competent programmer not being to solve that problem on a whiteboard, which is precisely the point.