We look at various parameters : Current company ( We match people from similar companies and never from the same company ) / university / coding performances across websites, including InterviewBit / interaction with design content on InterviewBit.
Based on that, we match people with almost similar backgrounds and enable them to interview each other. If you are already interviewing through InterviewBit, we give higher preference to finding a peer who is currently working at one of the companies you might interview at.
A similar matching happens to figure out the problem to be asked from you.