Workflow

Codebase Understanding

Rapidly map architecture, identify key modules, and understand unfamiliar code before making changes.

Overview

When joining a new project or diving into unfamiliar code, use this workflow to quickly map the architecture, understand dependencies, and identify key modules. Instead of spending days reading code manually, Claude Code can scan the entire repository and provide a structured overview in minutes.

When to use

Use this workflow when starting on a new codebase, planning a large refactor, onboarding team members, or investigating a subsystem you haven't worked with before.

Step-by-step process

Start with context

Describe what you're trying to learn and why. This helps Claude focus on relevant parts of the codebase.

"I'm new to this Next.js project. Help me understand the authentication flow and how user data is managed."

Request architecture mapping

Ask Claude to identify core modules, their relationships, and the overall system structure.

"Map out the main directories, identify the authentication system, and show me how components communicate with the API."

Deep dive on critical paths

Once you have the overview, drill into specific flows like data processing, API routes, or state management.

"Walk me through what happens when a user logs in, from the form submission to session creation."

Document your findings

Have Claude generate a summary document with the architecture map, key files, and next steps for your reference.

"Create a markdown file summarizing the auth system architecture with links to key files."

Example prompts

Understanding a new framework setup

"This is a Django REST API project. Explain the project structure, where models and serializers live, and how authentication is configured."

Investigating a specific feature

"Show me all the code related to the checkout process. What files are involved? How does payment processing work?"

Mapping dependencies

"What are the main external dependencies in this project? Which ones are critical vs nice-to-have? Are there any security vulnerabilities in the current versions?"

Finding entry points

"What are the main entry points to this application? Show me where requests come in and how they're routed."

Expected outputs

Architecture diagram

Text-based or markdown representation of the system's major components and their relationships

Key modules list

Annotated list of important directories and files with their purposes and responsibilities

Dependencies overview

Summary of external packages, their versions, purposes, and any potential issues

Data flow documentation

Step-by-step explanation of how data moves through the system for critical user journeys

Next steps checklist

Recommended areas to explore further or potential improvements to make

Best practices

Start broad, then narrow focus—get the 10,000-foot view before diving into specific files

Ask for file paths with line numbers so you can easily navigate to referenced code

Save the generated documentation to your repository for team reference

Combine codebase exploration with reading existing docs and READMEs

Use this workflow iteratively—you don't need to understand everything at once

Common pitfalls

Asking to explain everything at once

Solution: Break exploration into logical chunks: auth, then data layer, then UI, etc.

Not providing enough context about your goal

Solution: Be specific: "I need to add a new payment method" vs "explain the codebase"

Ignoring documentation that already exists

Solution: Ask Claude to read existing docs first, then fill gaps or clarify confusing parts

Pro tips

Use glob patterns to focus exploration

""Analyze all files matching src/auth/**/*.ts and explain the authentication strategy""

Ask for comparisons to familiar patterns

""Is this similar to a standard Rails MVC structure or something different?""

Request visual representations

""Create a mermaid diagram showing how these modules interact""

Combine with testing

""Based on the architecture, what unit tests should I read to understand the payment flow?""

Related workflows

Bug Fixing Refactoring Think First