Oh it's server side "rendering"?
To me “rendering engine” also means something else. Namely taking html and rendering it to the screen.
Consider updating your vocabulary because the term is often used for both.
Note that rendering to the “screen” really means writing bits at a memory range, which is just one interface for displaying things. Html is another, higher level interface these days.
"rendering engine" has a pretty clear meaning and is a pretty poor term to use for a system for tranforming one kind of text bits into another.
Perhaps you should consider using less confusing terminology in your vocabulary?
https://developer.mozilla.org/en-US/docs/Glossary/Engine/Ren...
Edit: You say "often used for both" but I am struggling to find any other examples. Yhe closest I can find is this extremely poorly named static site generator project: https://github.com/render-engine/render-engine?tab=readme-ov...
Edit2: Man, the appropriation of the term "rendering" by JS people has led to some pretty stupid stuff, like this statement: "SSR, short for Server-Side Rendering, is a technique in web development where the webpage's content is rendered on the server instead of the client's browser."