Su San Talks Tech

Dec 30, 2025 · Backend Development

How I Cut Category Tree Load Time from 3 Seconds to 30 Milliseconds

A real‑world performance disaster caused by N+1 queries in a SpringBoot project was solved by replacing recursive database calls with a single batch query, building an in‑memory hash map, and adding multi‑level caching, achieving a 100× speedup and dramatically reducing system load.