Loading learning content…
Loading learning content…
Use Claude Code to understand unfamiliar codebases, map architecture, and locate the right files fast.
Read through the lesson, mark it complete when the concept is clear, then move to the next lesson in the sequence or jump back to the module map.
When you drop into an unfamiliar codebase, resist the urge to ask Claude to make changes immediately. First, let it map the terrain:
Explain the architecture of this codebase. What are the main modules, how do they relate, and what does data flow look like?
Claude will read package.json, README.md, directory structures, and key files to build a mental model — and share it with you.
Claude Code uses a combination of glob matching, content search, and semantic understanding to find code:
Where is the authentication logic? Show me the middleware that validates JWT tokens.
Find all places where we call the Stripe API and list the endpoints used.
These queries work because Claude reads files — it doesn't just grep. It understands context.
One of the most powerful use cases: tracing a request from entry point to database:
Trace a POST /api/orders request from the route handler all the way to the database write. Show me every function that touches the data.
This kind of analysis used to take hours. Claude Code does it in seconds.
What are the 5 most important external dependencies in this project? What does each one do and why was it chosen?
Claude will read package.json, scan import statements, and synthesize an explanation.
Ask Claude to generate a visual summary:
Create a brief architecture summary I can paste into the CLAUDE.md so future sessions start with this context.
This creates a reusable artifact that speeds up every future session in the same codebase.
Before touching any code, ask:
If I need to change how users are authenticated, what files would I need to modify and what are the risks?
This kind of pre-flight analysis catches integration issues before they become bugs.