Understanding Monorepos and How Turborepo Makes Them Fast

After completing my learning of Next.js, I stepped into learning Monorepos and Turborepos, and the idea behind Turborepo fascinated me, knowing how it solves a major problem that has been ignored by most of us.

Before learning about Turborepo, we must first understand what a Monorepo is.

What is Monorepo?

Monorepo is a single repository that holds code for multiple projects (apps, packages, libraries).

Comparison of Monorepo with polyrepo (many separate repositories)

In a Monorepo, one repository holds multiple projects, libraries, or services, whereas in a Polyrepo, each project or service has its own repository.

Advantages of Monorepo

• Unified versioning - Easier to keep dependencies in sync.

• Atomic changes - Cross-project changes in one commit/PR.

• Centralized tooling - Shared build/test/deploy pipelines.

• Better visibility - One place to search and navigate code.

• Easier refactoring - Safe large-scale code moves/renames.

Challenges with Monorepos

• Builds get slower as the codebase grows.

• Dependency management becomes complex.

• CI/CD pipelines may take longer.

Introducing Turborepo

Turborepo is a high-performance build system designed for managing JavaScript and TypeScript monorepos.

It helps developers build, test, and deploy projects in a monorepo faster and more efficiently, with smart caching and parallel execution.

Advantages/Features of Turborepo

1. Incremental builds

   • Only rebuilds what has changed.

   • Speeds up development and CI pipelines.

2. Remote & local caching

   • Stores build outputs and reuses them, even across different machines or CI runs.

3. Parallel task execution

   • Runs build/test/lint tasks concurrently where possible.

4. Zero-config monorepo support

   • Easy setup with turbo.json - No need for heavy custom build scripts.

5. Optimized for JS/TS

   • Works great with tools like Next.js, React, Node.js, and popular package managers (npm, pnpm, Yarn).

How Turborepo Improves Monorepo Workflow

Incremental builds

• Only rebuilds the parts of the repo that changed.

• Skips unnecessary tasks for unchanged projects.

• Results: Faster local dev and CI runs.

Smart task orchestration

• Automatically determines task dependencies using a project graph.

• Runs tasks in the correct order.

• Executes independent tasks in parallel to use all CPU cores.

Local & remote caching

• Stores outputs of builds, tests, and lints.

• Reuses cached results if the input files didn’t change.

• Remote cache allows sharing results across team members and CI — so CI/CD can skip redundant work.

Zero-config monorepo structure

• Uses a simple turbo.json to define tasks (like build, lint, test).

• Automatically understands project relationships.

• No need for custom scripts or manual dependency management.

Consistent results

• Guarantees reproducible builds: same input → same output.

• Prevents “it works on my machine” issues.

Faster CI/CD pipelines

• Drastically reduces build times on cloud runners by restoring and reusing caches.

• Makes large projects deployable within minutes instead of hours.

Optimized for frontend workflows

• Designed for modern JavaScript/TypeScript stacks.

• Works smoothly with Next.js, React, Node.js, Vite, etc.

• Easy to integrate with tools like pnpm workspaces, Yarn workspaces, or npm workspaces.

Story Time

Turborepo was created by Jared Palmer to solve the pain of slow and inefficient builds in JavaScript and TypeScript monorepos, and after its success, it was acquired by Vercel in 2021 to become a high-performance build system that powers modern frontend teams with smart caching and fast, incremental workflows.