Heroku is a robust leader in 12-factor deployment strategies. It is a large and feature-rich platform. You can deploy your app knowing that you are sitting on top of one of the best infrastructures on the planet for deployment and hosting. Importantly, when you are on Heroku, you don’t have to deal with infrastructure entropy or software entropy. Software entropy is the tendency of web servers to become outdated, security risks, or just plain crash over time.
You can’t realistically launch your own server, virtual or not, and expect it to keep working forever without your intervention.
When you pull back the curtain and consider how complicated deployment is, you understand that what Heroku is really doing for you is a highly necessary job of maintaining the hosting infrastructure and deployment infrastructure over time , thus reducing your cost.
Heroku is well-documented, but there’s a nuance regarding using the root of your domain name (also known as “the apex”) this article explains.