The repo includes scripts that render Terraform files to deploy the infrastructure to Google Cloud in three regions and set up load balancing. Helm then sets up NFS access for WordPress via nfs-provisioner, SyncThing to synchronize the file system across regions (since WordPress stores e.g. uploaded media directly on the file system), and WordPress itself. Helm also provisions TiDB, which is a NewSQL database that can be used as a replacement for MySQL.
All in all, it is a nice demo and a reasonably minimal basis for a non-trivial application (as it uses both databases and a file system to store needed state) to geographically distribute.