I wonder if this is based on research. One might speculate that the performance-centric talents that are essential to low-level coding (filesystems, OSs, database engines) may not be the same set of skills that apply to high-level open-ended problem solving (such as figuring out a realistic algorithm to power a dating site, acknowledging human nature's role, or
architecting an AWS competitor, etc).
1. Former Coding Interview Question: Find longest word in dictionary that is a subsequence of a given string
2. Using strings in Java (Java For Beginners: Strings, String Functions & Chars)
3. Using arrays in Java (Java For Beginners: Arrays)
13. Java Object References
14. Sort array problem (considerably easier than the first problem although hash tables come after it)