I admit I have not experienced true REPL driven development as the author defines it, but I have created an easier way for "development with a REPL" in vim. I love it because it's like a looser, faster Jupyter notebook, and it works with any language that has a REPL.
It works by sending highlighted text to vim's terminal buffer. I wrote a short blog post with a demo and the vimscript code here:
Code is written and read by humans, therefore it should be clear and concise.
Cleverness should be used in constrained situations like performance (fast inverse square root [1] comes to mind), and comments explaining the cleverness is important.
I should note [1] did a terrible job at commenting.
https://github.com/jpalardy/vim-slime