Exploring pnpm: A High‑Performance Package Manager for Node.js

This article shares a highly useful package manager, pnpm, and begins by recalling the pre‑npm era when developers manually added library files or CDN links to projects.

It then outlines the four steps npm performs when installing a package: resolving version ranges, downloading tarballs, extracting them to a local cache, and copying them into node_modules .

Traditional npm used a nested node_modules structure, which caused large directory sizes and duplicated installations for shared dependencies.

With the advent of yarn and npm 3, the file structure was flattened, reducing duplicate installations and speeding up installs, but introduced issues such as ghost dependencies (undeclared dependencies that become reachable due to flattening) and the “split” problem where different versions of the same dependency may be hoisted inconsistently.

Lerna is mentioned as a monorepo tool that improves developer experience but does not solve the underlying package‑manager problems.

pnpm (performance‑npm) keeps npm‑compatible commands while radically changing the installation layout: it stores packages in a global content‑addressable store and creates hard links to a virtual store ( .pnpm ) and then soft links into the project’s node_modules , achieving a flat structure without the ghost‑dependency side effects.

Key advantages of pnpm are fast installations via hard/soft links, significant disk‑space savings, and built‑in monorepo support.

# Install all dependencies declared in package.json
pnpm install

# Install a package and add it to dependencies
pnpm install -S <package>

# Install a package and add it to devDependencies
pnpm install -D <package>

# Uninstall a package
pnpm uninstall <package>

# Link a local project to another (uses hard links)
pnpm link

The article concludes that pnpm offers a superior alternative to npm/yarn, though sharing a global store can cause cross‑project side effects if node_modules contents are modified directly; the official FAQ provides mitigation strategies.