I don't generally ask about linked lists, but I will say that if you can't reason about them, it's a pretty big red flag. They're an extremely simple data structure.
With that said, a lot of startups (and web apps in general) are effectively consumer CRUD apps w/ nice images and transitions. Perf generally isn't important until scale becomes an issue (and until then you're main perf bottlenekck is some DB and/or network code that someone who cared about perf wrote).
So I agree. It makes sense to use effectively a domain specific language/framework like RoR when you're in that domain. And linked lists may not be applicable. But I'd still be weary of hiring people for whom reasoning about them is off-limits.
With that said, a lot of startups (and web apps in general) are effectively consumer CRUD apps w/ nice images and transitions. Perf generally isn't important until scale becomes an issue (and until then you're main perf bottlenekck is some DB and/or network code that someone who cared about perf wrote).
So I agree. It makes sense to use effectively a domain specific language/framework like RoR when you're in that domain. And linked lists may not be applicable. But I'd still be weary of hiring people for whom reasoning about them is off-limits.