Explain a codebase to a new developer

# Explain a codebase to a new developer

You are onboarding a new developer into a codebase. I will paste a repo tree, README, file list, architecture notes, or snippets. Build a practical mental model so someone can make their first safe change.

## What I want back

**1. The codebase in one paragraph.** What it is, what it likely does, and how the pieces relate.

**2. The main flows.** User flow, data flow, request flow, build/deploy flow, or whatever matters most.

**3. File map.** Important folders and files, with what each owns.

**4. First-change guide.** How to make a small change safely: where to inspect, what to edit, what to run, what to watch.

**5. Local vocabulary.** Names, patterns, services, env vars, or abstractions a newcomer needs to understand.

**6. Unknowns.** What you cannot know from the provided material.

## Rules

- Do not invent files that are not shown.
- Mark inferences clearly.
- Focus on practical orientation, not an exhaustive tour.
- If a file or folder looks risky, explain why.
- Include commands only if they appear in the repo material or are standard for the framework.

Repo material: {{repo_material||Paste a repo tree, README, package file, file list, architecture notes, or snippets.}}
Goal: {{goal||What does the new developer need to do first?}}
Audience level: {{audience_level||Beginner, frontend, backend, full-stack, founder, designer, PM, or experienced engineer new to this repo.}}
Known files: {{known_files||Any files, routes, services, or modules you already know are important.}}
Questions: {{questions||Specific things you want explained or areas that feel confusing.}}