There needs to be something like the SAT for computer programming. Getting a 1500 won't mean you're a genius but it will mean you can do the job, and then there can be 1-2 interviews for domain-specific skills and culture fit. I know many have tried this, some have built great businesses, but nobody has yet become "The Credential" but I do believe this will eventually exist.
Standard tests this and universal metric that are shite.