This is a simple URL shortening service, written in Python using Flask and Redis.
$ nix-shell -p python3.pkgs.flask python3.pkgs.redis
[nix-shell:~/src/shortener]$ FLASK_APP=app.py flask run
* Serving Flask app "app.py"
* Environment: production
WARNING: Do not use the development server in a production environment.
Use a production WSGI server instead.