If you expect this to grow into a huge platform, as in completely replace LinkedIn, use Django, if not, use MeteorJS. Django will allow you to scale very quickly, as it is more robust. However, the learning curve for Meteor is much smaller and will allow you to get a very modern, reactive application up and running quickly.

thanks, that kind of info is useful to me.

If you are doing it as a CV showcase type thing looking for a job I would do it in C# , why are you doing it?

project for a friend that could become his business/SaaS platform.

Use diaspora or gnu social as a framework, the code is already there and open source.

thanks, looking into it!