How to Centralize App Config with a Single Validated Module in Node.js

Scattering process.env calls throughout application code creates untested, hard-to-maintain configurations that can cause runtime crashes when variables are missing or mistyped. A cleaner approach involves consolidating all environment variable reads into a single dedicated config module that validates, parses, and freezes the configuration at startup. This ensures missing required variables throw errors immediately on launch rather than failing silently during runtime. TypeScript users can further benefit by defining a typed interface for the config object, enabling autocompletion and compile-time checks. For local development, dotenv can load .env files within the same config module, while production environments rely on orchestrators like Docker or Kubernetes to supply real environment variables.