Node.js, the difference between development and production

There is no difference between development and production in Node.js, i.e., there are no specific settings you need to apply to make Node.js work in a production configuration. However, a few libraries in the npm registry recognize using the NODE_ENV variable and default it to a development setting. Always run your Node.js with the NODE_ENV=production set.

A popular way of configuring your application is by using the twelve factor methodology.

Why is NODE_ENV considered an antipattern?

An environment is a digital platform or a system where engineers can build, test, deploy, and manage software products. Conventionally, there are four stages or types of environments where our application is run:

• Development
• Testing
• Staging
• Production

The fundamental problem of NODE_ENV stems from developers combining optimizations and software behavior with the environment their software is running on. The result is code like the following:

if (process.env.NODE_ENV === 'development') {
  // ...
}

if (process.env.NODE_ENV === 'production') {
  // ...
}

if (['production', 'staging'].includes(process.env.NODE_ENV)) {
  // ...
}

While this might look harmless, it makes the production and staging environments different, thus making reliable testing impossible. For example a test and thus a functionality of your product could pass when NODE_ENV is set to development but fail when setting NODE_ENV to production. Therefore, setting NODE_ENV to anything but production is considered an antipattern.