.env.development.local [work]

Your team’s .env.development points to a shared staging database. You, however, are testing a new migration script and need to point to localhost:5432/my_local_db . Instead of modifying the shared file (and risking committing the change), you add DATABASE_URL=postgres://localhost/my_local_db to .env.development.local . When you switch to production mode, this file is completely ignored.

# OAuth Callback URLs (pointing to localhost) GOOGLE_CLIENT_ID=your-google-client-id.apps.googleusercontent.com GOOGLE_CLIENT_SECRET=your-google-client-secret .env.development.local

To understand its specific purpose, let's break down its name: Your team’s

Since .env.development.local is never committed, new team members need to know which environment variables are required. The standard solution is to commit a .env.example (or .env.sample ) file that lists all expected variables with placeholder values（）: .env.development.local