Community app w/ranking system.

My idea is actually just more of a twist on forums.

Gathering a community in the filmmaking community. There will be job postings, cinematographers, grips, directors and every other role on the site. You either make a job listing or apply for one, easy enough. And there is a ranking system, if you show up late to work, your rank drops signaling you're unreliable, but there will be those people who show up on time, who do their job and get ranked accoedingly. My only issue is how to prevent fraudulent ratings and getting members to start posting in the beginning.

Basically this app will hold people in this community accountable for their actions, just like an uber driver does and protects talents such as actors or models who think their photographer may be a weirdo or creep. But the fraudulent part is what concerns me.

Has anyone come up with something even remotely similar to this?What stumbling blocks did you have to overcome and did you ever over come them?