I've only skimmed some of the code, but fwiw, anyone can read their code for each framework that's benchmarked here: https://github.com/TechEmpower/FrameworkBenchmarks/tree/mast...

There's also a good amount of active discussion going on here: https://github.com/TechEmpower/FrameworkBenchmarks/discussio...

Here's the code for the JS (just-js) benchmark: https://github.com/TechEmpower/FrameworkBenchmarks/blob/mast...

And here's the code for the Python uvicorn benchmark: https://github.com/TechEmpower/FrameworkBenchmarks/blob/mast...

From some light skimming, the JS and Python code doesn't look particularly abnormal or overly-optimized.