This laser tracker uses Firebase (firebase.com) as its backend. Firebase is a realtime database as a service application that allows developers to build data driven applications without a custom server component. All the application specific code for the laser tracker is run in the browser and is hosted as static files.
Because there is no custom server component with Firebase the security model is a little different than your typical database driven LAMP-style application.
Firebase provides an authentication layer that can use usernames and passwords, and/or third-party OAuth authentication. Authorization rules are set by application administrator(s) which restrict read/write access to users authenticated through one of these mechanisms.
A typical database driven web application employs a general set of access rules for the application-database connection and it is left as an exercise to the application to restrict access to the database appopriately for the application users. In a Firebase application these rules are set directly on the database and the users have direct access to the data for which they are authorized.
Rather than tables with hard defined schema, Firebase data is stored as a nested object. Anything that can be represented as a JSON object can be stored in Firebase. JSON is used as the import/export and backup mechanism within Firebase.
Firebase is designed to be real-time. Rather than issuing queries and iterating over result sets, Firebase apps attach event listeners to part of the object store. Once attached events immediately fire for everything already stored there, and then again for anything that is added, changed, or removed. Most of the time nothing special has to be added to make Firebase applications work in a real-time.