Based on the fact that your ideal is to have a similar experience to heroku than managing your own server setting up reverse proxies take a look at these options:
1) https://dokku.com - lets you turn your light sail instance basically into heroku
4) If you have aws credits this is their heroku equivalent: https://aws.amazon.com/elasticbeanstalk
above is not what I do but would be the options I would pursue if I understand your preference and requirement correctly.