> And the obvious for any Django dev; select_related, prefetch_related, annotate

And sometimes not so obvious, I have been bitten by forgetting one select_related while inadvertedly joining 5 tables but using only 4 select_related: the tests work OK, but the real data has a number of records that cause a N+1. A request that used to take 100ms now issues "30 seconds timeout" from time to time.

Once we added the missing select_related we went back to sub-second request, but it was very easy to start blaming Django itself because the number of records to join was getting high.

The cases that we usually walk out of the Django path is for serializations and representations, trying to avoid the creation of intermediate objects when we only need the "values()" return.