If you have a large code base
When the code base is huge, and more than one person working on the project, the type system can help to avoid many common mistakes. This is especially true for single page applications.When the developers of your team have become accustomed to statically typed languagesTypescript substitute for a BabelWhen a library or framework recommend TypescriptWhen you really feel the need for speed
if(typeof name !== ‘string) throw ‘Name should be string’
With Typescript we can eliminate many of these types of checks all together.