📁 utils/
- Purpose: General-purpose helper functions.
- Characteristics:
  - Pure functions (no side effects).
  - Reusable across the app.
- Examples:
  - formatDate()
  - validateEmail()
  - generateRandomId()

📁 lib/
- Purpose: Library wrappers or core logic modules.
- Characteristics:
  - Handles I/O or integrates with external services.
  - Application-specific logic (e.g., DB, mail).
- Examples:
  - lib/prisma.js (Prisma client)
  - lib/redis.js (Redis connection)
  - lib/sendMail.js (Nodemailer wrapper)

📁 config/
- Purpose: Centralized application settings.
- Characteristics:
  - Environment/config values.
  - No logic, just definitions/settings.
- Examples:
  - config/database.js (DB credentials)
  - config/jwt.js (JWT secret, expiration)
  - config/app.js (port, app name)