Please read the requirement carefully .
If anything where service is similar with LinkedIn. There is many cloud services and free lancer work at many services.i.e. upwork review point is 4.5, freelancers review point is 3.9... . Freelancer can shelf registration and companies can search.
point is:
[login to view URL] like you can register your review this web system easily.
[login to view URL] including whatever all you have been register Crowd sourcing ([login to view URL],freelaner.lancers...)
[login to view URL] like us can search the freelancers and make sure freelancer's total review.
Above is my idea. If you can modify and add your idea to make a complete portal, please make a proposal with clear flow (make a diagram as well).
Looking forward for a fruitful proposal.
Please don't bid and waste your time if you won't make any proposal.
Happy bidding !!