In my case, I wanted to create a simple recommendation engine (the domain doesn’t matter so much). To do that, I had to import FAST 20 million nodes of one-to-many, sparse matrix data. This became a bit more complicated (and interesting) task than originally anticipated, so it became a mini-project itself.
Bulk insert is a scenario that every database should have it covered.
Original title and link: How to Import Large Graphs to Neo4j With Spring Data ( ©myNoSQL)