Drupal 8 is out the door – well, the release candidate at least, so it's time to get intimate with it. As I'm mostly a backend developer with a focus on coding, I'm mostly interested in what's under the hood: how should we write a new module. As we had our heating system upgraded this summer and I opted for a controller that can be instructed via the web, it was an extra motivational factor: it would be nice to have a heating system #madewithdrupal8.