There's a monthly "seeking freelancer" thread, or at least there used to be. I also always mention my comfort working contract with people even when I'm interviewing for full time roles, in case that's helpful for them. "Any way that gets the money from your bank account to mine".

Edit: Also, I do recommend the "startup match" system they run, I've been having good success with that this year, found my current role and a number of solid roles that were candidates for acceptance. Be forewarned, that there are many well-intentioned but unserious people on there, so you definitely have to do a ton of legwork. Don't judge a book by it's cover, some of the best roles were people who frankly seemed somewhat unhinged but ended up being really interesting and compelling.