Services that help freelancers find each other?

Question

Freelance

Let's say a designer is looking for a developer to realize his idea. Or a developer is looking for a collaborative theme designer at themeforest.net/. Or a developer + designer team is looking for a manager who will supply them with clients. Etc.
Are there appropriate services to facilitate such a search?
Upd. Clarification was required: we are not talking about hiring a developer or designer. The same theme for Temforest is the division of risks in half. If the topic succeeds, the income is shared, otherwise, no one gets anything.

Answer 1

Are there appropriate services to facilitate such a search?

Freelance exchanges.

Clarification needed: we are not talking about hiring a developer or designer. The same theme for Temforest is the division of risks in half. If the topic succeeds, the income is shared, otherwise, no one gets anything.

It won't work. Therefore, one person must get a certain amount of money that is needed to pay a small team of specialists for some time, until an investor comes, the project reaches self-sufficiency or closes.
By the way, there are a majority of such people on ordinary freelance exchanges in the role of a client.
I myself will never trust a leader who cannot pay for a team of specialists: his lack of money means that he does not have a positive experience.
And therefore, the percentage of profit that he will offer will be from zero.
And if he has experience, then he will not offer a percentage to developers, because a fixed amount will cost him less.

Answer 2

This is called a freelance exchange
fl.ru weblancer.ru for
rush upwork.com elance.com for the world
you hang up a job in an hour fifty applicants will write to you.