• $195

How to Read Code - The Missing Manual

  • Course
  • 54 Lessons

.Reading code is a skill nobody teaches.

You learned to write code. But nobody taught you how to read it—how to land in an unfamiliar codebase and actually understand what's going on.

So you do what everyone does: grep around, add print statements, hope for documentation that doesn't exist. It works, eventually. But it's slow, frustrating, and you never feel confident you understand the full picture.

This course changes that.

You'll learn the systematic approach experienced developers use to read and understand code quickly:

  • Find entry points — Where does execution actually start?

  • Trace data flow — Follow information through the system

  • Identify patterns — Recognize common architectures at a glance

  • Build mental models — Understand the "why" behind the code

  • Navigate efficiently — Use your tools to move through code fast

Whether you're onboarding to a new team, reviewing pull requests, debugging production issues, or evaluating open source libraries—you'll have a repeatable process that works.

Stop guessing. Start understanding.

Contents

Introduction

Everything is code
Humans in the loop
Who is this for
You have everything you need
The five modes of reading

Foundation Concepts

What is cognitive load?
Bounded context simplified
Abstraction vs Concretion
Why layering matters
Understanding scope
Jobs To be Done
Schema formation

Set Up

Ergonomics
GitHub and OPP
Package Managers
Virtual Environments
What the heck is an IDE?

Previewing

Intro to Previewing
Conventions and cognitive load
Case Study: Joplin
Previewing with Copilot
Mental Model: What are the bounded contexts?
Mental Model: What are the architectural layers?
Mental Model: What jobs does the software do?
Previewing with Visual Code

Skimming

Intro to Skimming
Outline view
Type hierarchy
Call hierarchy
Minimaps
Folding

Scanning

Intro to Scanning
Fuzzy find
Symbol search
Find references
Find concrete classes
Find concrete methods
Bookmarks

Detailed Reading

Intro to Detailed Reading
Zen mode
Syntax highlighting
Parameter hints
Error warnings
Programmer Comments
Copilot "Explain this"

Critical Reading

Intro to Critical Reading
Human Review
Pull Requests
Comparing Things
Pull Request Review Exercise
Git logs
Programmer Intent
Tests
Debugging