Is processing data using python function and calling it with Dash only frontend?

Hello everyone,

I plan to use Dash in my company and I have some questions. I made a python program to process CSV into dataframes for making studies.

I want to display those DF using Dash. The objective is the following: the user upload CSV files one by one, Dash stores it in user session cache (server sided) and call python functions from my program to process them together (merge, clean, etc.) as dataframes and update the front (plotting and info) accordingly. The data will be store with memoize.

Once the user is done uploading, it can chose to save those files in the server or not.

My question is the following: will the processing (merging, cleaning, etc.) of DF be done in front or back end? I don’t know Flask, so I will be using Dash only. I will be dealing with big amount of data so it is something I need to know.

By reading the doc, I have the impression that regarding data processing, Dash is for front end only, but I am not sure since I have never developed for web.

To put it simply: I want to know if, from Dash, calling functions in my python program makes the processing front or back end. For processing, Dash will call functions from another directory, but in the same project as my Dash app. Also, with hughe amount of Data (more than 1Go per user, up to 10 or 20 users), will cache.memoize() have enough space?

If it is front end, do you have any solution?

Thank you for your attention and sorry if it is a stupid question, I have no knowledge of web development.

Processing will be all on the backend unless you use javascript clientside callbacks