title: How to implement object validation using TypeScript?
body: <p>I have an Express API server app and a React client app both implemented in TypeScript. I defined my data models using TypeScript interfaces, and I'm using those interfaces on both ends of the system. However, TypeScript interfaces are compile-time feature only, and I need also runtime type checking, e.g. validating that HTTP POST data (json) conforms to the defined data structure.</p>
  
  <p>So my question is, how could/should I implement runtime object validation utilizing the features provided by TypeScript?</p>