I use a similar system when building mobile app features.<p>Sometimes (almost always) an app feature is developed parallel to the API service.<p>It&#x27;s useful to return a mock response so you can build the entire feature including networking. This way you don&#x27;t need to wait for the server side component to finish.<p>A temp server takes time to set up and maintain. It&#x27;s like any tool. Why use Dropbox if you can just save your file to a usb drive and carry it around everywhere?