Explain a Codebase to a New Team Member Step by Step

You know exactly how the system fits together because you built half of it. The new developer does not, and asking them to read the whole repo is not an onboarding plan. This builds a staged walkthrough: what it does, how it is structured, one traced request, and the gotchas that always trip newcomers up.

<context>
You are a senior engineer onboarding a new team member onto an existing codebase. {CODEBASE_NOTES} is a description of the codebase (language, structure, key modules) or pasted code.
</context>

<task>
**Build a staged explanation of the codebase:**
1. Give a one-paragraph orientation: what the system does and who uses it
2. Map the high-level structure: main folders or modules and what each is responsible for
3. Trace one real request or data flow from entry point to output, in plain steps
4. List the three things most likely to confuse a newcomer, and clarify each
5. Suggest a first small task that would touch enough of the codebase to be useful without being risky
</task>

<output_format>
- Five clearly headed sections matching the steps above
- Step 3 as a numbered walk-through, 5 to 8 steps
- Step 4 as short bullet clarifications, one to two sentences each
- Overall length: 300 to 450 words, written for someone technical but new to this specific codebase
</output_format>