[donw]

Even outside of e-commerce -- I would say anything on the web.

Run something like Ruby/Python for the majority of your web services, and deploy Elixir/Go/Kotlin/C++/Swift whenever you hit a data-munching need that Ruby/Python can't handle.

This doesn't fly if you're doing games, or augmented reality (AR), or mobile apps, or embedded stuff... but the web is still a pretty big place to build.