How to make an application to handle 2.2 mil unique requests per day?

The project is for a social media platform, where the application will run on a server and the users will interact with it through the social media messaging platform. The app will handle about 2.2 million unique requests per day.<br><br>Here's the stack:<br><br>- The social media platform has a "REST API" that will be used for interaction with the users. This is where we'll receive the requests and send the responses. (General idea: "REST request" -> "REST call" -> "social media call" -> "social media responds to us" -> "social media platform responds back to the user").<br>- Front-end: The application will have a web interface. This is used to configure the app and to present statistics. The web interface will be used by just a few people, but they'll be using it constantly.<br>- Back-end: The requests from the social media platform will be received by a "REST API". These will be processed, each one of them, by a python script. <br>- Databases: "this will have 5 million entries of the users that interacted with our application". We'll also have a smaller database to save the interactions with the application. I am planning on using SQLAlchemy. Another important point is that each interaction, will require to make a REST call to a third party API (we'll have around 12 REST calls).<br><br>I've made the application before, but with a very small number of users (not close to 2.2 mil). What I am afraid of is that my application won't be able to handle that many requests and that the database calls are going to slow down my application significantly.<br><br>So here's what I am asking:<br><br>- Is python (with Flask or Django) a correct choice for this type of application? Because I think it is not going to be able to handle that many requests.<br>- Is it better to make the application to run on multiple servers, or to run it on a single high-power server? (I am planning on using AWS, but if another service is more reliable and cost-effective, please let me know). <br><br>Thanks for the help. Let me know if I can simplify the problem.