NODE_ENV=production definitely wasn't set based on some basic testing I did (that's my PR there), which accounts for the atrocious performance.
Also, the React component is created on each request instead of just being created once. Unless one's goal is to specifically colour the perception of React, I don't understand that decision alongside the code for Pug which precompiles the template a single time.
(Also declaring the map function outside the component and not creating a closure makes for a tiny extra boost.)
It's disappointing to see that the article took off to this extent given how misleading and inaccurate it is.
What's more, it doesn't even signal that the individual in question is better at their job than someone that puts in "only" 40 hours. I've worked with a good number of people who can talk big-talk when it comes to programming, have a countless innovative side-projects and yet can't deliver anything meaningful at work by the deadline. Some of them had very impressive github accounts and worked 10+ hours a day, but were consistently behind everyone else in the quality of their output.
I think it's a shame if someone quits the profession because they think they need to keep up with people who might or might not be delivering actual business value.