Where will the information about the presence of a free problem be placed to attract the necessary specialist? Will this list be added to your database by the participant who adds the project?
I think registration will not be necessary to see free projects. But in order to take part in them you will certainly need an account.
The one who proposes the project, himself recruits a team of participants and gives access to the project, or anyone can participate? How to confirm their qualification in this case?