Backend Development on Muhammad Hassan Razahttps://mhassan.dev/categories/backend-development/Recent content in Backend Development on Muhammad Hassan RazaHugoen-usSat, 15 Nov 2025 10:00:00 +0500I Shipped a Race Condition That Double-Charged Customers (And Other War Stories)https://mhassan.dev/blog/war-stories-from-production/Sat, 15 Nov 2025 10:00:00 +0500https://mhassan.dev/blog/war-stories-from-production/The production bugs I actually shipped, how they failed in the real world, and what fixed them.Optimizing Django ORM Queries for Large Applicationshttps://mhassan.dev/blog/django-orm-optimizations/Mon, 17 Feb 2025 12:00:00 +0500https://mhassan.dev/blog/django-orm-optimizations/Django ORM query fixes that improved billing performance by reducing relation loading mistakes, repeated writes, and inefficient loops.Optimizing Django Signals for Efficient Ledger Recalculationshttps://mhassan.dev/blog/using-signals-optimally/Sat, 15 Feb 2025 12:00:00 +0500https://mhassan.dev/blog/using-signals-optimally/A Django signals cleanup pattern for ledger recalculation that batches work after commit instead of triggering redundant writes.