[Answer]-Django slow at creating objects?

If you install Django debugtoolbar you could actually see the queries being fired, and the code responsible on firing them.

This slowness is mainly because django fires a new db query every time you do e.mobile and e.contact_owner, in the loop.

To prevent these queries, prefetch the data using select_related like below

query = Contact.objects.select_related('mobile', 'contact_owner').filter(contact_owner=batch.user, subscribed=True)

If your relations are many to many, then use prefetch_related rather than select_related.