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.