I currently work at an organization that has a lot of very flaky applications that are spread across a handful (5, 10, 20) servers using zookeeper, ignite and a

I currently work at an organization that has a lot of very flaky applications that are spread across a handful (5, 10, 20) servers using zookeeper, ignite and a few other frameworks that attempt to provide "clustering". It all ads a lot of overhead and isn't particularly reliable - frankly, I think it would make mor sense to run it on a mainframe, and have simple application code because the fault tolerance is on the hardware/OS layer. If you are a big tech company, then the massive scale means the cost advantage of x86 is worth dealing with node failures and it's not like any single mainframe for handle it, but for a lot of internal applications that are too big for any single x86 machine, but don't require thousands of nodes, I can totally see where it makes sense.