Do you have examples of primitives that are hard to replicate? I can't think of many off the top of my head.
> tables and IPC
Sure, kdb doesn't really have an equal, though it is very niche. But for IPC I disagree. The facilities in k/q are neat and simple in terms of setup, but it doesn't have anything better than what you can do with cloudpickle, and the lack of custom types makes effective, larger-scale IPC difficult without resorting to inefficient hacks.
