- Yearly view: replace N*12 queries with annotate/ExtractMonth (6 queries) - Fixed expenses: bulk_create instead of get_or_create loop - Use DB aggregate(Sum) instead of Python sum() for totals - Remove 10 unused CRUD views, 13 URLs, 6 templates, 3 forms - Fix overly broad Exception catch in save_expense - Move update_budget to app/monthly/services.py (no cross-handler imports)