Module Overview

What You’ll Learn

• Explain what actually changes between a development environment and a production one
• Configure an application differently per environment without duplicating code
• Manage secrets correctly across multiple environments

💡 Why this matters: Every course in this track has run on localhost, with one .env file, one developer, one set of assumptions. Production has multiple environments, real secrets, and real consequences for a misconfiguration, this module is where that gap gets closed first, before anything else in this course makes sense.

What’s Covered

• Environments, what development, staging, and production actually mean, and why they need to differ.
• NODE_ENV, what it controls, and what it doesn’t, by default.
• Per-environment configuration, structuring settings so the same code runs correctly everywhere.
• Secrets across environments, keeping production secrets out of development, and out of source control entirely.

Hands-On

By the end of this module, you’ll have a Node.js application that behaves correctly and safely across three distinct, real environments, from a single, well-structured codebase.

Next module: process management, keeping that application actually running, reliably, once it’s live.