Most slow Django apps aren't slow because of the ORM. They're slow because of a few repeatable mistakes that get worse as tables grow.

Quick wins

Measure first

print ( Order . objects . filter ( status = " paid " ). explain ( analyze = True ))

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Fix N+1

orders = ( Order . objects . select_related ( " customer " ) . prefetch_related ( " items " ) . filter ( status = " paid " )[: 1000 ] )

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Load fewer columns

emails = list ( User . objects . values_list ( " email " , flat = True ))

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Keyset pagination instead of deep OFFSET

def next_page ( last_id = None , size = 100 ): qs = Order . objects . order_by ( " id " ) if last_id : qs = qs . filter ( id__gt = last_id ) return list ( qs [: size ])

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Bulk writes and DB-side updates

Order . objects . bulk_update ( changed_orders , [ " status " ], batch_size = 1000 ) Order . objects .…