Cosign opens a curated professional network for the startup ecosystem

Cosign has opened a beta professional network for startup investors, operators, founders and companies. Instead of relying only on self-written profiles, the site organizes reputation around “cosigns” from people who have worked together, plus user-curated lists and community comparisons. The public product also includes an industry activity feed and startup job listings. Cosign's site credits a16z, whose accounts promoted the launch, but the beta has not established whether its endorsement model will produce better hiring or investment signals than existing networks.