TypeScript is a typed superset of modern JavaScript. While we do not recommend TypeScript for all JS projects, it especially makes sense to ADOPT it for business-critical algorithms and core domain logic in JS.


  • implements type safety in JavaScript; with support for explicit nullables, generics, type inferrence, JS interop and lots more
  • great support in VS code


  • harder to set up with webpack and babel based build


  • flow type - seems to be a little less popular than TypeScript, but still relevant in the space.
  • ReasonML - a type safe functional programming language coming from OCaml, and being able to compile to JavaScript. Built from the same people who invented React; so that's why I'd watch this language!