An interesting take on dynamic gemini pages: You add %%%-delineated code-blocks which execute shell code.
The output is displayed.
You can have inline variables mimicking shell variables prefixed with % as well (e.g. %$my_awesome_variable).

With those two building blocks you have a very simple concept, but leadin gto powerful dynamic execution:
Want to execute an advanced python script? Just call it from your shell code!

I am not entirely sure about security implications, however.