In 2014 Yann Malet and I (with the help of the rest of the team here) wrote a book about building and scaling Django websites. It was the culmination of things we'd learned from, at the time, close to a decade of experience building, deploying, and supporting Django sites.
It's been seven years since its release and it's fair to say that the book has run its course. While I didn't feel good about continuing to sell the book given its age, I also believe it still contains a lot of valuable information. As you'd expect, after seven years, many of the technical examples are outdated. The book, however, is largely conceptual. Code snippets are rarely the "secret sauce" when scaling a site. Topics such as caching and reducing/optimizing database queries aren't usually coding challenges. In fact, thanks to the stability of Django, much of that code is still the same today.
So instead of relegating the book to the dustbin, we're releasing it for free online. It's something we've wanted to do for a long time and I'm excited to finally get the book in more people's hands.
You can find it on this site at https://lincolnloop.com/high-performance-django/.