I've been around a few companies migrating from EY/Heroku -> AWS and the cost effectiveness is always astonishing. In addition you gain full control over your architecture, which is a major plus.

And how much more engineering time do you waste on it now?

Interested in how you achieved this. Did you change server setup significantly from the default EY stack?

I'm curious about this too, especially the last part (similar / identical stack) ?