Hi,
Yes, you should use systemd or another process manager (e.g. supervisord). I don’t have readily a tested configuration unfortunately, but you can take a look for example at my earlier post with upstart example - https://www.sharetribe.com/community/t/how-to-run-sharetribe-in-background/281/2 - and then at this guide: https://wiki.ubuntu.com/SystemdForUpstartUsers.
When you get your systemd configuration working, it would be awesome if you share it here!
Yes, we are using Heroku. Looks like the Heroku runtime is built on Ubuntu 14.04.
Cheers,
Boyan