Here are some of the links that Mark mentioned:

https://markgalassi.sourceforge.io/workshop-prep/
https://markgalassi.sourceforge.io/workshop-prep/modern-software-eng.html
https://markgalassi.sourceforge.io/workshop-prep/2020-modern-software-eng-handout.pdf

https://github.com/unoconv/unoconv  # deprecated, see unoserver
https://github.com/unoconv/unoserver/

Regards,

- Robert