[lambda]

> Whether or not this is the case, I don't know, but it kinda feels like running your app on a shared-hosting account...

Remember that you are running your app on a shared hosting account with Heroku.

Now, it has somewhat more isolation than a typical shared hosting account, but less isolation than using physically separate hardware.

Heroku is built on top of AWS, so your machine is running on the same physical hardware, though a different virtual machine, as other AWS customers. Furthermore, Heroku uses LXC to isolate its dynos; so you are running on the same VM as another Heroku customers, albeit separated by a container barrier. And finally, if you're using Postgres, then you're running on a shared database service, which is pretty much exactly like what you'd get with shared hosting.