vercel/turborepo ? reverse-engineered prompt

Build me a fast build tool for JavaScript and TypeScript monorepos, with a simple command line experience and smart task caching so repeated runs are much quicker.

I want it to understand a workspace with multiple apps and packages, figure out what depends on what, and run the right tasks in the right order without making me babysit it. It should be easy to configure from a small project config file, work well in normal TypeScript and Node projects, and feel polished enough to use in a real team.

Make it production ready, with clear commands, good error messages, and documentation that explains how to get started. If you need to check current docs or best practices online, go ahead and look them up.