The main issues for these applications were caused by trying to run a development system’s code, tested on AWS instances on a physical, on-premise cluster running on real data. The original developer was never given access to the production cluster or the real data.
Apache Ignite was a huge source of problems, principally because it is such a new project that nobody had any real experience with it and also because it is not a very mature project yet.
I found this article fascinating, particularly because the answer was a lot more than just “throw some more hardware at the problem.”