Is it possible for a launched sub-process from an op to continue running even after that op is done ?

depending on how the subprocess is launched and managed yes it is possible for it to continue running

If there'll be some example of how to achieve this - would be great to see it 👀

theres not much dagster special about it so looking at how to do it for python in general should get you in the right direction looks like

start_new_session

on

Popen

may be promising https://stackoverflow.com/questions/5772873/python-spawn-off-a-child-subprocess-detach-and-exit