A monorepo contains multiple projects in a single repository. When managed well, monorepos enable code sharing, atomic changes, and simplified dependency management. When managed poorly, they become slow and unwieldy. Here's how to get it right.
Why Monorepos?
Benefits
✓ Atomic changes across packages
✓ Single source of truth
✓ Simplified dependency management
✓ Easier code sharing
✓ Consistent tooling
✓ Better visibility
Challenges
✗ Build times can grow
✗ CI complexity increases
✗ Git operations slow down
✗ Ownership can be unclear
✗ Learning curve for tools
Monorepo Structure
Typical Layout
my-monorepo/
├── apps/
│ ├── web/ # Next.js web app
│ ├── mobile/ # React Native app
│ └── api/ # Node.js API
├── packages/
│ ├── ui/ # Shared component library
│ ├── config/ # Shared configs (ESLint, TS)
│ ├── utils/ # Shared utilities
│ └── database/ # Database client
├── turbo.json # Turborepo config
├── package.json # Root package.json
└── pnpm-workspace.yaml # Workspace definition
Workspace Definition
Build Tools
Turborepo
Key features:
- Task caching (local and remote)
- Parallel execution
- Dependency graph awareness
- Incremental builds
Nx
Key features:
- Computation caching
- Distributed task execution
- Project graph visualization
- Code generators
Package Management
Internal Dependencies
Shared Configurations
TypeScript Configuration
Task Orchestration
Running Commands
With Turborepo
Caching
Local Caching
Remote Caching
CI/CD Optimization
Affected-Only Builds
Parallel Jobs
Code Sharing Patterns
Shared Components
Shared Types
Versioning and Publishing
Changesets
Best Practices
Ownership
# CODEOWNERS
/apps/web/ @frontend-team
/apps/api/ @backend-team
/packages/ui/ @design-system-team
/packages/database/ @platform-team
Consistent Scripts
Dependency Hygiene
Documentation
Conclusion
Monorepos shine when you need tight coordination between packages, shared tooling, and atomic changes. Modern tools like Turborepo and Nx make them practical even at scale.
Start with a clear structure, invest in shared configurations, and leverage caching aggressively. The upfront investment pays dividends in developer productivity and code quality.
The key is treating the monorepo as a product—it needs maintenance, documentation, and continuous improvement to serve your teams well.