/teach

For when understanding has decayed or a new developer needs to get up to speed.

When to use

• Haven’t touched the codebase in a while
• New team member joining
• Need to understand an area before working on it

What it does

1. Gauges your level: refresher, domain expert but new to code, or completely new
2. Walks through the system in layers:
   • What does this system do? (context)
   • What happens on the happy path?
   • What happens when things go wrong? (failure modes)
   • What must always be true? (invariants)
   • How do the pieces connect? (integration points)
3. Optionally quizzes: “If the queue stops flushing, what are the three most likely causes?”
4. Generates a study guide with strong areas, focus areas, key files, and a safe first task

Output

A study guide. Understanding in the developer’s head.