Re-assigen rank # after altering count, (Removing, adding)

So i have a list of items, each with their own Rank # that was assigned according to order of creation.

I want when an item #2 is deleted, item #3 should become #2, etc.

How would i do that automatically?

You’d probably need to run an API workflow on a list

What kind of action can do this?

You’d create the API workflow to update the rank on everything with a number greater than the one you deleted. Then, on the delete action, you would schedule that API workflow