When Guido was the BDFL (but whom am I fooling, everyone still will blindly accept a PEP from him and his opinion will still weigh a ton, steering council or not), he was pretty actively against any kind of bytecode-level optimization even though a lot could be done that way, citing “simplicity” and “readability”. Most Python core developers have had pretty much a Pavlovian response to shut down any and all such discussions.

I think they could get away with it for a while because none of the competing implementation would readily steal Python’s darlings, namely NumPy/SciPy and Tensorflow. Now there is competition, and it can really push CPython away to being a niche “reference implementation”, thus we are seeing these twitches.

The track record of CPython core team in the last decade makes me very wary when it comes to bringing in such features. Ship it or it didn’t happen.

P. S. Microsoft once threw a large sum of money at Kenneth Reitz to work on Requests, anyone remembers how that story ended?

Reitz is no core dev, guido has always delivered. His track record is flawless.

However, the first release will probably suck like asyncio or type hints did.

It will take time to become usable, but it's unlikely it won't happen.

Reitz is no core dev, true, but he serves as an illustration and a cautionary tale of what can happen if you throw large sums of money at seemingly-prolific people hyperactive on socmedia.

Namely, that it’s absolutely not guaranteed to work.

What track record does GvR have in terms of speeding up CPython? He did not care for 3 decades (which is a defensible position given C extensions) and has been literally called "the boat anchor" by another HN member many times.

Mypy was Jukka Lehtosalo's work, asyncio was fixed and extended by many.

So now he needs a project at Microsoft, he changed his mind (or had it changed under pressure) and this is the project. We'll see, I agree though that the first version will be underwhelming, the following versions will have a max speedup of 50% but will be celebrated at conferences and here.

Sorry, I don't debate with throwaway accounts, they are usually trolls.

The only person with JIT experience listed there seems to be Mark Shannon. GvR may push through whatever is developed though.

If that is cause for excitement can be seen when a product is finished.