Make Cursor Work with Large Codebases (5+ Files)

When you started, Cursor was perfect. It understood your 3-file project completely. Now your project has 20+ files, and Cursor is lost:

• Suggests rebuilding features that already exist
• Changes one file, breaks three others
• Can't find functions you know exist
• Forgets what files connect to what
• Makes you explain your project structure every single time

Your codebase isn't too large. Cursor just needs help tracking it.

Why Cursor Struggles with Large Projects #

Cursor works great with small projects because it can see everything at once. But as your project grows:

Small project (3-5 files):

• Cursor sees all files simultaneously
• Understands all connections
• Makes accurate changes
• Never breaks working code

Large project (20+ files):

• Can't see everything at once
• Loses track of connections
• Makes changes based on incomplete info
• Breaks things accidentally

It's not that your project is "too large." Real apps have lots of files. The problem is Cursor tracking those files without help.

The Manual Approach (Free but Time-Consuming) #

You can create documentation that helps Cursor track your large codebase.

Step 1: Create Project Map #

Create .cursor/codebase-map.md:

## Codebase Structure
 
## Core Features (Don't Rebuild These)
- Authentication: auth.ts, login.tsx, signup.tsx
- User Profiles: profile.tsx, ProfileCard.tsx, editProfile.tsx
- Settings: settings.tsx, SettingsForm.tsx
- Database: database.ts (used by ALL features)
- Email: email.ts (notifications, password reset)
 
## How Features Connect
- Login page → auth.ts → database.ts → user profiles
- Profile changes → database.ts → email.ts (notification)
- Settings → database.ts → all features (theme, preferences)
 
## Critical Files (Be Careful)
- database.ts - Used by everything, changes affect entire app
- auth.ts - Login/signup depend on this
- types.ts - Shared across all features

Step 2: Add File Headers #

In each major file, add comments at the top:

// USER PROFILE MANAGEMENT
// Used by: settings.tsx, dashboard.tsx, profile.tsx
// Uses: database.ts, auth.ts, email.ts
// DO NOT modify without checking dependent files
 
export function getUserProfile(userId: string) {
  // ...
}

Step 3: Tell Cursor to Check #

Before every request:

Read .cursor/codebase-map.md first, then [your actual request]

Pros: Free, you control it

Cons:

• You must maintain it manually
• You have to remember to tell Cursor every time
• Gets outdated as you build
• Still not as effective as automatic tracking

The Automated Approach (Saves Time) #

Giga automatically tracks large codebases for Cursor.

Setup (5 minutes):

npm install -g giga-cli
giga init
giga connect cursor

What it does:

• Scans all your files automatically
• Maps how features connect
• Updates as you build (no manual maintenance)
• Works regardless of codebase size
• Cursor knows your entire project structure

What changes:

• Cursor stops suggesting rebuilds of existing features
• Changes to one file don't break unrelated files
• No need to explain project structure in every chat
• Cursor finds functions and files accurately
• Building feels like it did when project was small

Signs Your Codebase Is "Large" for Cursor #

Don't wait until confusion is severe. Set up tracking when you hit 10+ files.

Common Large Codebase Problems #

Problem: Cascade Breaking #

Symptom: Change one file, three unrelated features break.

Why: Cursor doesn't see that File A is used by Files B, C, and D.

Manual fix: Tell Cursor every dependency:

Before changing auth.ts, note that it's used by:
- login.tsx
- signup.tsx
- profile.tsx
- settings.tsx
Make sure changes don't break these.

Automated fix: Giga maps dependencies automatically. Cursor sees what connects before changing.

Problem: Duplicate Features #

Symptom: Ask for a feature, Cursor builds it from scratch even though you already have it.

Why: Cursor forgot that feature exists in your codebase.

Manual fix:

We already have user search in search.tsx.
Update that file instead of creating new search.

Automated fix: Giga maintains feature list. Cursor checks existing features before building new ones.

Problem: File Chaos #

Symptom: Project has 30 files. Cursor changes random files you didn't mention.

Why: Cursor is guessing which files are relevant.

Manual fix: Specify exact files every time:

Only modify these files:
- dashboard.tsx
- DashboardCard.tsx

Do NOT touch:
- auth.ts
- database.ts
- [list 20 other files]

Automated fix: Giga organizes file relationships. Cursor knows which files are relevant to each request.

How to Work with Large Codebases #

Strategy 1: Modular Architecture #

Organize your code into clear modules:

/auth
  - login.tsx
  - signup.tsx
  - auth.ts
/profile
  - profile.tsx
  - ProfileCard.tsx
  - editProfile.tsx
/settings
  - settings.tsx
  - SettingsForm.tsx

This helps both you and Cursor understand structure.

Strategy 2: Shared Files Documentation #

For files used everywhere (database.ts, types.ts), create docs:

# database.ts
 
CRITICAL FILE - used by all features
 
## Functions
- getUser(id) - Used by: profile, settings, dashboard
- updateUser(id, data) - Used by: profile, settings
- deleteUser(id) - Used by: settings only
 
## Dependencies
- All user features depend on this
- Changes here affect entire app
- Test thoroughly before committing

Strategy 3: Feature Flags #

When building new features in large codebases:

// New feature - not fully integrated yet
const ENABLE_NEW_SEARCH = false;
 
if (ENABLE_NEW_SEARCH) {
  // new code
} else {
  // existing code
}

This prevents new features from breaking existing ones.

Strategy 4: Regular Context Resets #

If using manual approach, update your codebase map weekly:

• Add new features to map
• Update connections between features
• Mark deprecated files
• Document new dependencies

Testing in Large Codebases #

After Cursor makes changes to large projects:

Test 1: Direct feature Test the feature you changed.

Test 2: Connected features Test features that import/use the changed files.

Test 3: Critical paths Test core user flows (login, signup, main features).

Test 4: Unrelated features Click around features you didn't touch. Make sure nothing broke.

Large codebases have more breaking opportunities. Test more thoroughly.

Migration Strategy #

If your large codebase is already messy:

Week 1: Document current state

• List all features
• Map file connections
• Identify critical files

Week 2: Set up tracking

• Implement Giga or manual docs
• Test with small changes

Week 3: Clean up confusion

• Ask Cursor to fix existing breaks (now it can see full project)
• Consolidate duplicate features
• Remove dead code

Week 4: Normal development

• Build confidently
• Cursor works accurately again

Advanced: Multi-Repository Projects #

If your project spans multiple repos:

Challenge: Cursor can't see code in other repos.

Manual solution: Document cross-repo dependencies:

# External Dependencies
 
## API Service (separate repo)
- Endpoint: /api/users
- Used by: profile.tsx, settings.tsx
- DO NOT change frontend user structure without checking API
 
## Shared Types Package
- Types imported from @myapp/types
- Changes require updating package version

Automated solution: Giga can track multiple repos together, showing Cursor the full picture.

When to Scale Up Your Approach #

Start with basic tracking, upgrade as project grows:

10-20 files: Basic codebase map document

20-40 files: Detailed map + file header comments

40+ files: Automated tracking (Giga) becomes essential

100+ files: Automated tracking + architectural documentation

Don't overcomplicate early, but don't wait too long either.

Common Questions #

How many files is "too many" for Cursor? #

There's no hard limit. It depends on complexity, not just count. A well-tracked 100-file project works better than an untracked 20-file project.

Will organizing files differently help? #

A bit, but organization doesn't solve the tracking problem. Even well-organized large projects need tracking.

Does this mean I should keep projects small? #

No! Build what users need. Just set up tracking so Cursor can handle it.

Can I split my project into smaller projects? #

Technically yes, but that creates other problems (deployment, dependencies, maintenance). Better to just track your large unified project properly.

The Bottom Line #

Large codebases aren't the problem. Lack of tracking is.

Your project has 20+ files because it's real and useful. Don't limit your app's capabilities just to keep it "small enough for Cursor."

Instead, give Cursor proper tracking so it can handle any codebase size.

Then build as large and complex as your users need, without AI breaking things.

Make Cursor handle your large codebase → Try Giga