Should Repository for building app and back end be separated or put together?

my co-worker from front end use framework7 to build android app. i don’t know anything about it. but i had experience on node.

because both of this use node, should i make one repository for app and back end (api) or should it be separated? so i’ll put that api on web-dev repository.

Doesn’t really matter, just do it in the way you are more comfortable with