Normally I wouldn't solicit people to sign up on HN, but since you asked for sources I figured I'll take the opportunity to help fulfill your search: https://www.codersclan.com/, if you sign up, mention you are the poster from HN and I'll make sure to speed the process up for you. Do note that the hourly rates start from $30/hour and that right now we're mostly looking for WordPress or front-end devs.
Another source you might want to look at is https://remote.co/ I think we even advertised there in the past, but naturally the type of work you'll get will depend on the contract you land.