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Introduction to Claude Code

Introduction to Claude Code

Code is no longer the bottleneck. The era of vibe coding has arrived.

Before: 1 PR per week. Hours debugging. Side projects never finished.

Now: 1 PR per day. Features in parallel. Products that ship.

Before You Start: Is This Course For You?

This course assumes you already know how to code (even at a basic level). We won't teach you to code from scratch - we'll teach you to code 10x faster with AI.

Quick Checklist

This course IS for you if:

  • ✅ You can create a basic project (React, Node, Python, etc.)
  • ✅ You understand what Git is (branches, commits, push)
  • ✅ You've used the terminal/command line before
  • ✅ You want to multiply your velocity significantly

This course is NOT for you if:

  • ❌ You've never written code before
  • ❌ You don't know what a variable or function is
  • ❌ The terminal feels intimidating

If you're in the "NOT" group: Start with a basic programming course first (freeCodeCamp, Codecademy). This course will be here when you return.

Your Level = Your Path

If you are...Focus on...Skip...
Junior (0-2 years)Entire course in orderNothing - absorb everything
Mid-level (2-5 years)Modules 2-5, Extended ThinkingBasic setup
Senior (5+ years)Memory, Automation, TeamsInstallation, basic modes
Team LeadTeam patterns, Org CLAUDE.mdHands-on tutorials

What is Claude Code?

Claude Code is Anthropic's official CLI tool that brings Claude directly into your development workflow. Unlike web-based assistants, Claude Code:

  • Lives in your terminal alongside your other tools
  • Has full access to your codebase
  • Can read, write, and modify files
  • Executes commands and sees results
  • Maintains context across your entire project

Why Claude Code Changes Everything

Traditional AI coding assistants work like this:

  1. You copy code from your editor
  2. Paste it into a chat window
  3. Get suggestions back
  4. Manually apply changes

With Claude Code, the workflow becomes:

  1. You describe what you want
  2. Claude Code implements it directly

This isn't just faster—it fundamentally changes what's possible.

The New Development Paradigm

Claude Code enables a new way of working where you:

  • Think at a higher level - Focus on architecture and design, not syntax
  • Iterate faster - Make changes across your entire codebase in seconds
  • Learn continuously - Claude explains what it's doing as it works
  • Reduce cognitive load - Let Claude handle the tedious parts

Quick Glossary

Terms we'll use throughout this course:

  • CLI (Command Line Interface): The terminal where you type commands
  • Token: Unit of text the AI processes (~4 characters = 1 token)
  • Context: The information Claude "remembers" in a session
  • PR (Pull Request): Request to merge your code into the main branch
  • Branch: A parallel version of your code to work without breaking anything
  • YOLO Mode: Mode where Claude executes without asking permission (dangerous but fast)

What You'll Learn

  1. Strategic setup - Installation and configuration that works from day one
  2. CLAUDE.md system - Persistent memory so Claude never forgets your architecture
  3. The 3 working modes - When to use each for maximum speed without breaking anything
  4. Advanced Git workflows - Branches and worktrees for parallel work without chaos
  5. Context management - Keep Claude focused on large projects
  6. Specialized sub-agents - Testing, reviews, and docs that happen automatically
  7. Automations with hooks - Commands that execute themselves
  8. Bulletproof testing & CI/CD - Deploy to production with confidence

For Team Leads: The Business Case

If you're evaluating Claude Code for your team:

Typical ROI:

  • Developer at $80K/year = $40/hour
  • 2 hours saved/day = $80/day value
  • Claude Code cost = $20-50/month
  • ROI: 40-80x in the first month

Metrics to track:

  • PRs per week (before vs after)
  • Code review time
  • Bugs in production
  • Team satisfaction

Risks to mitigate:

  • Over-dependence (rotate between with/without Claude)
  • Security (MCPs, permissions, secrets)
  • Code consistency (organizational CLAUDE.md)

Challenge: Your First Win Today

Before continuing, do this (5 minutes):

  1. Install Claude Code: npm install -g @anthropic-ai/claude-code
  2. Create a test folder: mkdir my-first-project && cd my-first-project
  3. Start Claude: claude
  4. Ask for something simple: "Create an index.html file with Hello World"

If Claude created the file, you've successfully used Claude Code. The rest of this course is optimization.

Next Steps

In the next lesson, we'll dive deeper into installation and configuration for real projects.