Very well done. I think the production pipeline is fully automated, including the cover. This is a very nice use of the CC BY licensed Stack Overflow content.
The Huffman coding example page shown for "Algorithms Notes for Professionals" is paraphrased from the classic textbook "Introduction to Algorithms", or CLR as it is often called. The tree diagrams on p. 54 of "Algorithms Notes for Professionals" are pirated directly from CLR -- p. 339 of my 2000 printing, but it may differ in later editions -- and the text is similar (CLR p. 338: "This method requires 300,000 bits to code the entire file. Can we do better?" Notes for Professionals p. 54: "This method requires 300,000 bits to code the entire file. Now the question is, can we do better?". I suppose they hired people in low cost-of-living countries to find the relevant reference materials and paraphrase them.
If you go to the bottom of the page for any book (well, I only sampled a few so "any" may be exaggerated), it says:
"The [LANGUAGE] Notes for Professionals book is compiled from Stack Overflow Documentation, the content is written by the beautiful people at Stack Overflow."
Ah that makes sense. I glossed over "Documentation" originally, so I thought it was somehow cleaned up from vanilla Stack Overflow answers. Was wondering how that cleanup got done
