> But pure Python is inherently slow because of language design. It also cannot be compiled efficiently unless you introduce constraints into the language, at which point you're tackling a subset thereof. No library can fix this.

A similar point was raised in the other python thread on cpython the other day, and I’m not sure I agree. For sure, it is far from trivial. However, GraalVM has shown us how it can be done for Java with generics. Highover, take the app, compile and run it. The compilation takes care of any literal use of Generics, running the app takes care of initialising classes and memory, instrumentation during runtime can be added to add runtime invocations of generics otherwise missed. Obviously, this takes a lot of details getting it right for it to work. But it can be done.