This was a strange article for me to read. It starts out with a long discussion of Node's "single-threaded compute / multi-threaded I/O" model as if it were a problem for compute-bound applications. But multithreading doesn't magically make compute-bound tasks go faster. Multiprocessing does, but you can fork a Node server so it runs across multiple processors quite easily.

(Keeps reading...) Ah, about halfway through the article they talk about introducing multiprocessing using the `cluster` module. But then they say the process is tied up until the request is fully received, bottle-necking the process based on client speed, which is not how I understand Node to work at all. Sure, the slow connection will tie up a socket and memory, so a buffering proxy makes sense, but it shouldn't affect compute. Maybe it's a limitation of `cluster`? My experience is with `worker-farm`.

Which brings me to the second oddity: CPUs are fast. What is Airbnb doing that takes so much compute? Perhaps server-side React is slow? On my own, admittedly low-traffic Node site, I use jade/pug for templating, and the initial template compile step can be expensive. But then I cache the compiled template and everything is too fast to care about thereafter.

I don't doubt that they had a problem, or how they fixed it, and I enjoyed this deep dive. Nonetheless, their reasoning about the underlying causes don't ring true for me.