Hi Samira, interesting question.
In my humble experience/opinion going on 9 yrs here: it's a mix. I socialise more with fellow expats and half swiss/half soemthing else-ers.
However Swiss contacts usually require more of a Stamm-something/regular contact like hikingbuddies, work buddies etc. I guess maybe I go out more as an expat whereas if I lived in my town in Ireland I'd have more family social opportunities like local Swiss.
Finally of course there's the romantic route which is probably the most successful "integration" route.