What is Rush?

Rush is a tool created by Microsoft that helps developers manage large codebases made up of many separate projects (called a monorepo). It automates tasks like installing dependencies, building, and publishing, so everything stays organized and runs smoothly.

Let's break it down

  • Tool: a piece of software you run from the command line.
  • Created by Microsoft: built and maintained by the same company that makes Windows and Azure.
  • Manage large codebases: keep track of lots of files and folders that belong to many different parts of an app.
  • Monorepo: a single repository (folder) that holds many related projects instead of one repo per project.
  • Automates tasks: does repetitive work for you, like downloading libraries, compiling code, or publishing packages.
  • Stays organized: makes sure each project uses the right versions of shared code and runs in the right order.

Why does it matter?

When many teams work on a shared product, keeping every piece in sync can become chaotic. Rush removes most of the manual steps, reduces version conflicts, and speeds up the development cycle, letting teams focus on building features instead of fixing build problems.

Where is it used?

  • Large web applications that consist of dozens of micro-frontends, each in its own folder.
  • Companies that ship many npm packages from a single repository, such as Microsoft’s own Office or Azure SDKs.
  • Open-source projects that want contributors to run a single command to set up the whole codebase.
  • Enterprises that need strict version control across many internal libraries.

Good things about it

  • Consistent builds: guarantees every developer gets the same result, no “works on my machine” surprises.
  • Smart caching: reuses previous build results, making incremental builds much faster.
  • Version policy enforcement: automatically checks that shared dependencies stay at approved versions.
  • Scalable: designed to handle hundreds of projects without slowing down.
  • Integrated with npm/Yarn: works with the package managers developers already know.

Not-so-good things

  • Steeper learning curve: the configuration files and commands can be intimidating for beginners.
  • Less flexible for tiny projects: the overhead may feel unnecessary for a repo with only a few packages.
  • Limited ecosystem: fewer plugins and community extensions compared to more popular tools like Lerna or Nx.
  • Requires Node.js environment: teams not using JavaScript/TypeScript cannot benefit directly.