As someone who has used both Flow and Typescript for years, I'd recommend Typescript over Flow. You can use Babel to compile Typescript code just like you can w

As someone who has used both Flow and Typescript for years, I'd recommend Typescript over Flow. You can use Babel to compile Typescript code just like you can with Flow and have Typescript do its type-checking in CI. Typescript has better editor integration, more type-definitions for libraries, and breaks compatibility much less often than Flow.