Which do large tech companies use?

Google, Facebook, and Microsoft use massive monorepos with custom tooling (Bazel, Buck, Rush). Smaller companies and startups often start with polyrepo for simplicity, then migrate as coupling increases.

Monorepo vs Polyrepo

Differences, use cases, and when to use each

A monorepo stores all projects/packages in a single repository. A polyrepo (multi-repo) uses separate repositories per service or package. Monorepos simplify cross-project changes; polyrepos enforce service boundaries and independent deployments.

Quick Comparison

Feature	Monorepo	Polyrepo
Structure	All projects in one repo	One repo per project/service
Cross-project Changes	Single atomic commit	Multiple PRs across repos
Build Times	Slower without tooling (nx, turborepo)	Faster per-repo builds
Team Boundaries	Shared codebase visibility	Strong team isolation
Versioning	Single version or workspace versioning	Independent per package

When to Use Each

When to Use Monorepo

Use a monorepo when you have tightly coupled packages, want atomic cross-package changes, or want to share tooling and components across projects in a single organization.

When to Use Polyrepo

Use polyrepo when teams need strong independence, services have different deployment cycles, or organizational boundaries make a shared codebase impractical.

Pros & Cons

Monorepo

Atomic cross-package commits

Shared tooling and dependencies

Easier code sharing

Tooling required for scale (nx, turborepo)

Access control is all-or-nothing

Polyrepo

Strong team autonomy

Independent deployment cycles

Simpler per-repo CI

Cross-package changes require multiple PRs

Dependency drift between repos

Verdict

Monorepo for tightly coupled projects and teams that collaborate often. Polyrepo for independent services and teams. Many large companies (Google, Facebook) use monorepos with specialized tooling.

Try the Tools

Diff Viewer

Frequently Asked Questions

All Guides All Tools