Suddenly, every useful gem that allows you to throw together an app in 5 minutes had to be rewritten from the ground up. Things like authentication, pagination, etc. which could be done in 10 minutes in a standard Rails app took days.
The worst part is that I was not permitted to contribute these customs gems back to Open Source. He was a very selfish person who used almost exclusively proprietary software and thought that any of the long hours we spent to rebuild all of these basic puzzle pieces to work with Neo4J would give other people a leg up or advantage - as if competitors out there would decide to build a direct competitor with our identical tech stack and we wanted to slow them down as much as possible... sorry boss, but if they wanted to build a competitor prototype they would just build it with an SQL relational database and have the entire app done in 2 weeks.
About 3 months into the project I mentioned to someone at a technology meetup that I was building in app in Neo4j.rb and he laughed at me. I was drinking the graph koolaid still at the time and tried telling him about the advantages. He told me that as soon as the app was deployed I would see how much extra work I would have in-store for me. To be fair, he was right. Migrations just didn't work the same. Eventually I was discharged from the company because I did not agree with the management's unethical business practices and continue doing shady things and agree with their moral jusitifcations for crimes so the app never actually saw the light of day.
I am sure there are many production apps succeeding with Neo4j, but in the end I just saw a project whose scope was 10x what it should have been. If you have a "slow" app that launches 3 months earlier than your competitor, you still win.