I did this on my current project. Basically: - Set up your TypeScript config - Set up Typings (or some other type def manager) - Rename all ".js" files to ".

I did this on my current project. Basically: - Set up your TypeScript config - Set up Typings (or some other type def manager) - Rename all ".js" files to ".ts" - Replace all "var x = require()" calls to "import x = require()" - Gradually refactor components (controllers, directives, services) to classes, or at least add type annotations to everything. Because TypeScript is a superset of JavaScript, you can work on an untyped system and add gradual typing until the codebase starts looking nicer. Any new functionality can be implemented in TypeScript; any existing functionality can be slowly refactored when it is touched by changes.