That's a pretty bizarre answer to what was a pretty reasonable question. I don't even see how the question and answer are related honestly. Surely the question is more about finding a better storage format for the initial ingestion or data storage and has little to nothing to do with POSIX.
Most languages have a way to slurp a file into memory in a single function call, after all. The fact that files exist shouldn't be a barrier here.
They’re using python and C/C++ to speed up the slow bits. Can’t imagine anything more portable than that without even having to know what posix is doing under the library abstractions.
When I was programming with Java-EE I was surprised how much effort had to be put in to produce the production artifacts: .Wars and .Ears and so on. I had to use a language called Ant. I also had to write Java, JavaScript, CSS and HTML.
On the C-side it is "make" or something similar. It means you must master multiple languages, some of which may be statically typed while others are not.
I assume integrating C with Python is similarly lots of overhead which in principle you shouldn't have to do. Why can't I just write everything in a single language and be done with it? Why do I have to write a program that transforms my source-code modules into an executable?
Most languages have a way to slurp a file into memory in a single function call, after all. The fact that files exist shouldn't be a barrier here.