This article gives an overlook of Typescript features that let us provide safety guarantees for our code unlike any other mainstream language. Typescript is a somewhat paradoxical language. It is a superset of Javascript and Javascript has one of the simplest, least strict typing systems among mainstream languages, where even distinction between int and float or char and string are deemed excessive. Javascript is also dynamically typed, a trait that may seem down-right harmful to developers coming from Java or C# background. And yet, Typescript, sitting on top of JS type system, allows us to model types far more strictly than any other mainstream language.

Article is quite big, owning to almost 4 years of complex Domain Modeling experience in Typescript that I'm attempting to sum-up and considerable amount of ways in which Typescript technical aspects can be applied to Domain Modeling. First part of this article explains the languages features of Typescript that we will use and is most useful to developers coming from other languages. If you are up to speed with TS, you can jump to the second part, which covers their application.