In a tutorial on building a Strapi quiz app, the creation of a new Strapi v4 app is necessitated due to incompatibility with Strapi v3, requiring the backend to be rebuilt from scratch. The process involves generating four content types: Question, Quiz, Answer, and Score, and modifying API routes and controllers to handle quiz scoring and answer management efficiently. The tutorial focuses on extending the Score controllers to calculate scores from user answers and adjusting permissions for API plugins to differentiate between public and authenticated user access. Additionally, sample questions and quizzes are created to be displayed on the front end, with a future plan to enhance the Angular 13 frontend for user sign-up, login, and score tracking. The tutorial is part of a series, with continued development planned for the Angular application.