what do you mean a one-off project? some of these have corporate/institutional backing but thats not the point. if you know how to implement machine learning models then there should be nothing (except maybe availability of pretrained models) preventing you from using common lisp. if you dont want to dig deep and are happy using just the front end (perfectly acceptable) then python is a much better bet
all the needed ingredients are there to build a custom production class ml solution in common lisp: vectorization, cuda, blas, lapack
Do any of those libraries linked above provide an example of training a resnet or bert on a GPU? I’m not looking for anything fancy, or production quality, just a basic example.
although not necessarily bert or resnet the following probably has all the ingredients for what you are looking for. the author of this library is a research scientist at deepmind since 2015
There's not even a convolutional layer provided as a building block. This project looks pretty dead to me: most of the code is 8 years old, and the last code-changing commit is over 2 years old. I guess it's okay as a proof of concept for ML with Lisp, but I don't think anyone interested in ML would actually consider using it.
In defense of common lisp: The language is ansi standard and hasn't seen core changes in decades. This means cl pagckages can be "done". It is very common in cl to have projects that haven't been touched in years, because it is highly unlikely to break, hence, "it just works". As for this specific ML conversation, I am not in this field and have nothing valuble to say about who uses what and how viable/appropriate any of the approaches(languages) are for ML.
i work in ml and you asked for an example so i thought a proof of concept answer is sufficient. as i said somewhere else if you are looking for a ready made framework then this is not for you and should probably stick with pytorch, tf, and maybe even pyro. but if you are willing to engineer your own system for optimal performance while avoiding c++ then you would be served good by common lisp. common lisp for ml is suited for software engineers doing ml not so much statisticians