Well if you ever do build it and post it here I bet you’d get a lot of signups. Especially if you built in an easy referral system where people could send mass invites to their friends if they log in through Google for example.

But I actually wonder if you need the “social graph” at all at first. You could start by making it a place where people post jobs and apply for them. The network effects will come later. All you need is maybe a simple algorithm that matches users to postings they might qualify for.