In what universe? People use Java, C#, Go, Node etc services that are 40% or more slower than equivalent C ones, and they're just fine with it...

Yes, it’s probably fast enough to be perfectly usable.

The point here is that implementing new features will be impossible, because this relies on an existing implementation that is not in python.

It is therefore not a proof that arbitrary high performance applications can easily be written in python.

It is simply an example of how high performance applications based on existing implementations someone else had written in another language can be wrapped in python.

>The point here is that implementing new features will be impossible, because this relies on an existing implementation that is not in python.

Isn't that the opposite? Implementing new features will be easier, because it uses the C backend a helper library (for parsing, eventing), so all the business logic is Python which is easier to extend.

This is also why people use embedded Python/Luc/etc in games, 3D programs, and so on.

If it was pointed out to their higher-ups that their infrastructure costs could be reduced by a sizable amount by changing language they might not be so fine with it.

The last thing most higher-ups care about are infrastructure costs and optimizations.

And in many cases you're the higher up, and startup founders take decisions to use slower but more flexible technologies every day...