This "Processing" gif tells the user absolutely no information. How about providing the user with some sort of status updates

[Naesen8585]

Use Asynchronous communications protocol like with socket-flask and socket.io in order to allow the user to get live updates on the output of the current actions of the server. It would be ultimately nice if there could be some sort of live calculated status bar. Otherwise, the user just sits there and wonders if there legitimately is anything happening while staring at the unhelpful, nebulous "Processing" gif.