http://toptal.com/

Toptal is a network of top-quality freelancers in software development, design, and finance. Only the highest rated freelancers are eligible to join Toptal, and the site connects the top 3% of freelancers to buyers in need. To connect with a freelancer, provide information about what you need, and Toptal will find your perfect match.

There is a no-risk trial period when working with new freelancers, so buyers don’t have to worry about paying for unsatisfactory services. Buyers can also browse top freelancer profiles and contact them directly to discuss work. Prices vary depending on whether buyers want to hire by the hour, part-time, or full-time.

Specialization: Toptal is a social network where buyers can meet top freelancers.