totally possible to learn a lot of economics and statistics and never have formal coursework in numerical methods for optimization.
Seems to be the case here. Regardless of the author's educational background, kudos to them for continuing to dive deeper into the math. After a math degree and three years of graduate school, I still run into blind spots almost every day, for topics that people across the hall from me would consider elementary.
I checked the guy’s LinkedIn, he has 5 years of econometrics and data science education. I am honestly perplexed how anything in this article could come off as new to someone with such background.