This chapter taught us why and how to create a Neo4j cluster with different kinds of servers. After the concepts, we saw how to build a cluster. We also saw the magic of the bolt+routing protocol.
You learned that we can grow from a cluster of several credit card-sized computers like Raspberry Pis (https://www.raspberrypi.org/) to a cluster made from several clouds (you'll need a strong credit card for that).
We also saw a disaster recovery procedure to which I'll add this tip: