S-Line Filter: Edit Database

Один % убил мой индекс — поиск завис на 8 секунд 🔥 LIKE '%foo%' — это ловушка: процент в начале выключает индекс. На миллионе строк — 5 мс против 8 сек. #sql #postgres #postgresql #backend #python #django #программирование #разработка #databases #performance #sqlacademy

From Healthcare to Data Analytics: 2 Months to $70/hr

System Design: Building a Bulletproof Payment Gateway! 🚀 Basic payment setups fail during network timeouts. To block catastrophic duplicate charges, enforce client-generated idempotency keys (UUIDs). The server saves this key first; if a duplicate request arrives, it immediately returns the cached result instead of re-charging the buyer. Never overwrite database rows to update payment statuses. Instead, implement an immutable ledger where every state change—authorized, captured, or refunded—cre