I'm using both TypeScript and Flowtype for my projects, hence the second boilerplate repository on GitHub: https://github.com/jsynowiec/node-flowtype-boilerplat

I'm using both TypeScript and Flowtype for my projects, hence the second boilerplate repository on GitHub: https://github.com/jsynowiec/node-flowtype-boilerplate https://github.com/jsynowiec/node-flowtype-boilerplate Usually I tend to lean towards TypeScript due to: - Much better tooling and editor/IDE integration (I'm using vscode and WebStorm), - DefinitelyTyped repository and the availability of type definitions, - It's subjective but TS has better documentation and examples, Don't get me wrong, the Flow (and React) community is doing a great job and in my opinion Flow is a very good tool for static type checking. The real problem with both is the coverage/quality of type definitions and the amount of time it takes to create typedefs. Right now there are many more typedefs available for TypeScript and the community is stronger and more active. Also, right now one common format or conversion between definition formats is not possible, see: https://twitter.com/lbljeffmo/status/787692583350829056 https://twitter.com/lbljeffmo/status/787692583350829056