I have had some real luck with freelance professionals via platforms such as Freelancer, PeoplePer Hour, Fiverr, etc. This is where I started out as a Freelance before starting my own businesses. My number 1 suggestion would be PeoplePer Hour. You will want to verify their experience and credibility, interview and hopefully offer them a contract all within this platform. On these platforms all payment, contracts and legal terms are handled via the site. It's a good place to start without committing to contracting out a third party company. You can search for professionals with keywords that match your project or you can post a job of your own that individuals will bid on and go from there.
Feel free to contact me for a call to discuss how to properly vet candidates, how to avoid scams and for some referrals of my favorite freelancers for your business.