Not to give too much away.... 😉

MQTT:
> The IOT service also nicely fits our use case as it provides a MQTT protocol for websocket traffic, which is a lightweight protocol specifically designed for sending messages between devices.

> By using MQTT communication (vs. http requests) we can bypass the certificate requirement entirely, and send credentials over an encrypted connection as part of the sending process. We can also update and change these credentials as needed thanks to our authentication module without having to re-deploy the code. We are actively working to open source this module so others can benefit from it.

React:
> As we moved into the second phase and the new architecture, we opted to move to a more traditional “headless” or “decoupled” Drupal implementation. We rebuilt the entire front end from the ground up using React and nested it inside of a Drupal theme. We realize that usually a headless Drupal has a stand alone front end, so in this case we have coined the term “nearly headless” Drupal.