I am currently using neo4j for my masters thesis.
so far I have built an app using nodejs, neo4j ,googlemap and chart.js to simulate relationships between critical infrastructure.
I do get stuck along the way, but thanks to the rich support community of neo4j I always find a document that sheds light into whatever I am stuck or frustrated on.
By Critical Infrastructure, I mean National assets either Physical, Logical or virtual such as Electricity, Telecommunication, Transportation etc. which are critical for the well being of any nation.