Another place to look for remote developers is freelance websites. https://www.upwork.com/o/profiles/browse/ Just an example. A quick search can bring other names.
From my experience, many projects listed in freelancing site lacks Clarity in requirements, asks a lot of productivity for minimal costs.If someone manages good feedback, they can ideally be called a good developer. And yes you can filter by technology, type of projects (long, short, tight or trivial).
Your work culture and process, will be the driving factors in building a positive word of mouth and feedback. Only that can help in retention and additions in the longer term.