Codebase Onboarding Map (Claude Code)

MyProject — orientation What it is MyProject is a web application built with Node.js and Express, targeting small business owners. It provides a simple interface for managing customer data and generating reports. Stack + shape Language: JavaScript, Framework: Express, Datastore: MongoDB, Hosting: AWS. Directory count table: - src: 120 files - tests: 50 files - config: 10 files The path of one request 1. src/index.js:12 — entry point for the application 2. src/routes/user.js:20 — routing for user-related requests 3. src/middleware/auth.js:15 — authentication check 4. src/controllers/user.js:30 — business logic for user data 5. src/models/user.js:40 — data access for user data Where the rules live - src/config/constants.js — pricing constants, breaking things if changed incorrectly - src/utils/validation.js — validation schema for user input Traps - Duplicated logic in src/controllers/user.js and src/controllers/admin.js, must agree - Stale documentation in README.md, setup commands fail Where docs and code disagree - README.md claims API is rate-limited, but src/middleware/rateLimit.js is not implemented Read these five files first, in this order 1. src/index.js — entry point for the application, understand how requests are handled 2. src/config/constants.js — pricing constants and other important values 3. src/routes/user.js — routing for user-related requests, understand how data flows 4. src/controllers/user.js — business logic for user data, understand how data is processed 5. src/models/user.js — data access for user data, understand how data is stored and retrieved