Steve, hope you don’t take any offense from my comments.
The intro clearly states that “3 years ago, I literally got myself hired at Google using this strategy”. So, the article is not about real world, PR and stuff like that. It’s all about solving contrived interview problems. At least I don’t think you get much “find substring in a string” in your day-to-day work.
But, saying that, it’s your article, and it’s up to you in which direction you take it.