Monorepos & Workspaces (npm, pnpm & Turborepo)

A monorepo (monolithic repository) is a version control pattern where multiple projects, applications, and shared libraries reside inside a single repository. Workspaces are package manager features native to npm, pnpm, and Yarn that link these internal packages together automatically.

Instead of publishing shared UI components or utility functions to an external npm registry during development, workspaces create local symlinks inside node_modules. This allows applications like apps/web to import internal packages like @myorg/ui instantly with live code updates.

Separate repositories force developers to publish, version, and reinstall internal packages every time a shared component changes. Monorepos unify your codebase so changes across multiple applications and libraries can be made in a single atomic git commit.

However, running builds and tests across dozens of packages sequentially is slow. Build orchestrators like Turborepo and Nx analyze your monorepo dependency graph to execute tasks in parallel, skipping unneeded work via intelligent local and remote computation caching.

In npm workspaces, the root package.json defines a workspaces array listing package directories such as apps/* and packages/*. Running npm install automatically hoists shared dependencies to root node_modules and symlinks internal packages.

In pnpm workspaces, packages are defined in pnpm-workspace.yaml, and internal dependencies use the explicit workspace:* protocol inside package.json. Turborepo then uses a turbo.json file where dependsOn: ["^build"] instructs the task runner to build shared internal packages before compiling dependent applications.