HN user
I know games are constantly brought up as an example, but it's for good reason. Your frametime being 16.6ms instead of 20ms is the difference between a shipped feature and a cut one in a console title. And all the data and instruction cache thrashing caused by pointer chasing can (and does) absolutely make that difference.
I replaced a ton of pandas code with an embedded DuckDB for internal data application and got a massive performance boost and (arguably) cleaner code.
If you think that, you're not familiar enough with modern games as a service. Fortnite lives on the latest version of Unreal Engine, and Unreal Engine changed a lot from the initial Fortnite development until now with many new features, rewritten parts, and major refactoring of other parts. It's huge and constantly evolving, so it is similar to, i.e., browsers.
There are scripting languages integrations for Unreal done in form of plugins. For example: https://angelscript.hazelight.se/