Prestige will play a factor. They get applicants from ivy's, phds, etc. They pay top dollar for a reason. They don't take mediocrity because it'll be too costly to the business.

That said, you can stand out by being a specialist. You should be able to read and write code in your language of choice without constant access to reference materials for things like: a) Standard control structures (loops/if-then/etc.) b) Function, module, class, type, etc. definitions c) Common data types like arrays, lists, hash tables/maps/dictionaries d) Exceptions and other error handling techniques e) Code organization