For instance, the article itself suggests to use early/premature returns, while they are sometimes compared to "goto", making the control flow less obvious/predictable (as paxcoder mentioned here). Intermediate variables, just as small functions, can easily complicate reading of the code (in the example from the article, one would have to look up what "isSecure" means, while "(condition4 && !condition5)" would have shown it at once, and an "is secure" comment could be used to assist skimming). As for HTTP codes, those are standardized and not dependent on the content, unlike custom JSON codes: most developers working with HTTP would recognize those without additional documentation. And it goes on and on: people view different things as good practices and being simpler, depending (at least in part) on their backgrounds. If one considers simplicity, perhaps it is best to also consider it as subjective, taking into account to whom it is supposed to look simple. I think sometimes we try to view "simple" as something more objective than "easy", but unless it is actually measured with something like Kolmogorov complexity, the objectivity does not seem to be there.