Best Stack for a Modern, Scalable, High-Performance, high volume and Secure Web Application

What is the best stack (and what are the best practices) for such a stack? I understand it has to be stateless if it has to scale horizontally (please correct me if I am wrong).

On the front end, Angular seems to be a very mature stack (along with bootstrapNG or bootstrap NGx). Again, please correct if I have got it wrong or if there are options which meet requirements in a better way.

How do you go about

  1. Authentication, Authorization and security (also session management) for horizontal scalability
  2. Does it need a back-end web framework ? If it does, would DJango fit best? If not, what else ?

The application/SAAS involves using ML and AI and would involve data ingestion from various sources and output would be graphics.