Honestly, I think I could get someone with no raw SQL experience writing code that’s at least 50% faster within a few hours. There are so many footguns that ORMs completely ignore, and never warn you about.

Using a case-sensitive filter (default for Django) in a DB with case-sensitive collation (default in Postgres)? Django will helpfully cast the tuple and your query to UPPER to match it for you, and the former wrecks indexing.

Checking if a string ends with something else? Goodbye, index.

I _think_ the latter can be worked around in PG with a GIN index, but I’m not positive (I work with MySQL much more). And in any case, you’d have to know to create that, and I imagine most devs won’t.

Fixing seemingly tiny things like that have a massive impact on large table query speed.