Interfacing data systems

We create mutators that transform the data from databases models to our server applications expected models. Our server may talk to some API and so we transform this data model to what this API expects. Furthermore we transform this data model to a HTTP request data model with the help of some library such as `fetch` for Node.js. Similarly on the frontend, we transform data from its current model to an HTML document that the browser can interpret.

Therefore our job as developers is, for the most part, to create mutators and interfaces that transform the data from one system to provide it to another system.