Getting Responsive Django View
Easiest I think will be use ajax to start he simulator. Response for start request can be updated on the same page.
However, you will still have to think about how to pause,resume and stop the simulator started by earlier requests. i.e how to manage and manipulate state of the simulator.
May be you want to update that in DB.
I have a HTML page which has four buttons Start, Stop, Pause and Resume in it. The functionality of the buttons are:

Start Button: Starts the backend Simulator. (The Simulator takes around 3 minutes for execution.)
Stop Button: Stops the Simulator.
Pause Button: Pauses the Simulator.
Resume Button: Resumes the Simulator from the paused stage.

Each of the button when clicked goes on to calling a separate view function. The problem I'm facing is that when I click the start button, it starts up the Simulator through a function call in the Python view. But as I mentioned that the simulator takes around 3 minutes for completing it's execution. So, for the 3 minutes my UI is totally unresponsive. I cannot  press Stop, Pause or Resume button untill the current view of Django is rendered.
So what is the best way to approach this problem ? Shall I spawn a non-blocking process for the Simulator and If so how can I get to know after the view has rendered that the new spawned process has completed it's execution.