The job boards are nice but I feel the remote-only boards are still super niche. I’ve had more success with a plain Google query that limits its results to some HR SaaS tool.
For example: “Javascript remote site:jobvite.com” then filter for last 7 days.
Of course that moves the goalpost to knowing which domains are a good fit. But that’s super dependent on your region and of course not all platforms follow this url pattern.