Faced The Problem of EADDRINUSE: 3000 while Building my Project (Backend Focused)

Sep 7, 2025 · 1 min read · "I recently faced an EADDRINUSE: 3000 already in use error while running tests in my Express + PostgreSQL project. At first, it was confusing — my server worked fine with node src/index.js, but npm test kept failing because Jest tried to start anothe...