python3 -m venv .venv
.venv/bin/activate
python server.py

npm exec node index.js

while sleep 1; do curl localhost:3001/reload; done  # Test the server, itself

while sleep 1; do curl localhost:3000/reload; done  # Test the proxy.

While curl is running, edit server.py and add a comment and save it to trigger a reload. Alternative, kill the server and run it again.