For a fairly easy performance win, and for something which makes dealing with old cached CSS something a thing of the past - enable ManifestStaticFilesStorage.

First of all you'll need to edit settings.py:

# Use manifest static storage
STATICFILES_STORAGE = 'django.contrib.staticfiles.storage.ManifestStaticFilesStorage'

Then you'll need to edit any templates …

Although using Model.objects.create_or_update() with a Django model is extremely convenient, sometimes you might want to consider using it carefully with certain usage patterns.