Why is it not recommended to use the flask/werkzeug internal development webserver in production? What sort of issues can arise?
I'm asking because in work I'm being forced to do so and use a make shift cron to re-run the service every day!
If you're having to use a cron job to kill & restart it on a daily basis, you've already found a major issue with using the Flask development server. The development server is not written for stability, longevity, configurability, security, speed or much of anything other than convenience during development.
A proper WSGI setup will be faster, handle multiple connections properly and, most importantly for you, periodically restart your app process to clean out any cruft that might build up.