That's nearly 5 years old now, so even the bits of that which are backed up with actual data aren't of much use. Benchmarks of asyncio in python 3.4.1 are going to be wildly different than in later versions. I understand the argument he's trying to make about db access and performance, but modern benchmarks seem to disprove his argument, e.g. https://www.techempower.com/benchmarks/#section=data-r18&hw=... and https://www.techempower.com/benchmarks/#section=data-r18&hw=... .