Sounds like one of the many, many alternatives which "works" by just targeting a different subculture. This "representative body of code" idea is very strange to me - I don't have any such thing that I could bring to interviews, it's never occurred to me to write one, and my areas of specialization offer me no opportunity to generate one organically.

If this were the standard interview process, of course, I'm sure I could figure it out. There would be a site called "Leetportfolio", and I'd prep for interviews by implementing dozens of Leetportfolio mediums, and people would come to HN to complain about the obnoxious companies that expect you to include some Leetportfolio hards. For me this sounds significantly more time consuming and no less artificial or frustrating than Leetcode grinding.