Thank you ever So much for your detailed answer, I hope my article would've been helpful.

Firstly, about typos, Although I've used spell and grammar checker tools, there are still some remained to be fixed. It would be a great help if you could've mentioned typos, however, I'll scan the article once more.

Secondly, About topic #7, no it was not an aggregate or annotation, it was a huge nested query that even in rails we should implemented by Arel, I'm not familiar with anything like Arel in Django or how it could have been implemented in any other ways but I am eager to learn if there is any best practices to implement 3 layers nested queries. in Django. needless to say that query could not have been altered.

Finally, Thank you again for reading the article and giving me some advices, I am much obliged.