I deleted my comment on post #2 because it seemed a little harsh - this is actually a very good and helpful guide, thank you for putting this together!

That said, there are a few things that could be improved:

• MySQL authentication with versions > 8 is more easily done with "mysql2" library. This won't require changing the authentication code
• The "npm start" command in the repository needs to be changed to actually start the webapp
• Using "https" for the localhost can cause CORS errors
• Many of the code doesn't specify which file it belongs to, which can make this tutorial difficult to follow for beginners

Overall, great job, just a few suggestions.