I am betting that the author came up with the filtering method in 5 minutes or less and quickly got it working. The 10 paragraph blog post is the “hard” part:

I am betting that the author came up with the filtering method in 5 minutes or less and quickly got it working. The 10 paragraph blog post is the “hard” part: explaining to others who don’t have the same base knowledge. If I read it correctly, they do even less human-powered work than your solution. It just looks hard because the machinery is unfamiliar.