I've gone through so many freelance websites - right off the bat, let me tell you that if you think you're going to find a hot developer on Upwork you are sorely mistaken. No offense to the (apparently gazillion) developers on the Upwork site but dang, it's almost like they took one class and call themselves experts. I'm a developer so I'm extremely picky who I pull on to my team but I also don't have time to vet every candidate. I have to hand it to JointoHire - they are the real deal - they gave me qualified candidates with whom it was worth spending the 30 minutes to do my standard "live code" test. The developers were excellent!