What a monorepo needs (the real requirements)

A good monorepo package manager should handle: Workspaces (multiple packages/apps) Fast installs for big repos Deterministic lockfile (same deps everywhere) Good CI caching Minimal “dependency weirdness” (phantom deps, hoisting surprises) Good developer workflow (run scripts across packages, filtering, etc.) pnpm in monorepos (why it’s usually best) 1) Speed (especially after first install) pnpm keeps a global content-addressable store (one copy of each package version). Each project uses hardlinks into node_modules . Result: repeated installs are very fast, and huge monorepos benefit a lot. 2) Disk usage (big win) With npm, each workspace can duplicate the same packages across subprojects. With pnpm, packages are reused from the store. Result: smaller repo footprint and faster docker/CI layers. 3) Strict dependency isolation (less “hidden bugs”) pnpm is strict: If package-a doesn’t declare lodash in its package.json , it can’t import it just because some other package installed it. Th