Something like https://www.toptal.com/ or https://crew.co/ or even https://hired.com/ for example.
I've been freelancing for a while, mostly referrals but you know it's nice to get something else to fill the project pipeline with. I'll bookmark sites like these and when I get some free time, fill out the 20-page application with my portfolio. It inevitably takes at least an hour...
One place took a few days to tell me that even though they advertised remote, they weren't hiring people "in my region" (aka not SF/NYC).
Another place did a Skype call with a "recruiter" who couldn't tell me anything about project sizes, timelines, or availability for my skillset. They wouldn't share the blanket legal agreements they described for me to review before continuing the "application" process. And they wanted me to do 90 minutes of silly coding challenges before even confirming they had work.
And the other place just sent me a generic rejection letter ("not the best fit for our community at this time") that must have taken 5 minutes to write. I have no idea if I'm too expensive for their projects, the wrong skillset, or just too senior.
The sad thing is, I have no problem being too senior. I don't want to be on every platform if I'm getting junior level work. But when you're asking for people to jump through all these hoops, claiming that your platform is where it's at... It's just getting ridiculous!
Now, a couple years later... I didn't have such great luck. It seems to me that all the shitty companies are now officially on board at Hired. So I got a sea of bad offers, and I went through probably fifteen or twenty interviews, the vast majority of which were for companies with clear silo management problems. Lowball offers, people with expectations that clearly did not read my resume or my cover letter with my own expectations, slimeball hiring managers that will say anything...
And here's the kicker: The last time I used Hired, my "talent coordinator" person (the individual working for Hired that helps you with job searching) very nearly sent my resume and profile information to the company I was working for. That was the last straw and I immediately stopped using Hired, and recommended to my friends to not use them.
I would recommend you give them a try, but that you stay on your toes and you take everything with a grain of salt. Maybe I just had a string of bad luck with them last time.