I'm not sure why this is being downvoted. There's no evidence that the kind of instruction that e.g. Facebook gives its junior developers is meaningful for performance on average. However I bet hiring from top universities is definitely meaningful for performance on average.
A junior developer is going to have a lot of blind spots because of unknown unknowns. A team with both talented junior developers and experienced senior developers can utilize the raw ability of the junior devs while having the senior devs cover the blindspots. A team with only talented junior devs will likely make some great things but they’ll also wind up having crucial problems that will only late into the project.
